Multiplefield based code generator and decoder for communications systems
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 H—ELECTRICITY
 H04—ELECTRIC COMMUNICATION TECHNIQUE
 H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
 H04L1/00—Arrangements for detecting or preventing errors in the information received
 H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
 H04L1/0041—Arrangements at the transmitter end

 H—ELECTRICITY
 H03—BASIC ELECTRONIC CIRCUITRY
 H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
 H03M13/00—Coding, decoding or code conversion, for error detection or error correction; Coding theory basic assumptions; Coding bounds; Error probability evaluation methods; Channel models; Simulation or testing of codes
 H03M13/37—Decoding methods or techniques, not specific to the particular type of coding provided for in groups H03M13/03  H03M13/35
 H03M13/3761—Decoding methods or techniques, not specific to the particular type of coding provided for in groups H03M13/03  H03M13/35 using code combining, i.e. using combining of codeword portions which may have been transmitted separately, e.g. Digital Fountain codes, Raptor codes or Luby Transform [LT] codes

 H—ELECTRICITY
 H04—ELECTRIC COMMUNICATION TECHNIQUE
 H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
 H04L1/00—Arrangements for detecting or preventing errors in the information received
 H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
 H04L1/0045—Arrangements at the receiver end

 H—ELECTRICITY
 H04—ELECTRIC COMMUNICATION TECHNIQUE
 H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
 H04L1/00—Arrangements for detecting or preventing errors in the information received
 H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
 H04L1/0056—Systems characterized by the type of code used
 H04L1/0057—Block codes

 H—ELECTRICITY
 H04—ELECTRIC COMMUNICATION TECHNIQUE
 H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
 H04L1/00—Arrangements for detecting or preventing errors in the information received
 H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
 H04L1/0056—Systems characterized by the type of code used
 H04L1/0064—Concatenated codes
 H04L1/0065—Serial concatenated codes

 H—ELECTRICITY
 H03—BASIC ELECTRONIC CIRCUITRY
 H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
 H03M13/00—Coding, decoding or code conversion, for error detection or error correction; Coding theory basic assumptions; Coding bounds; Error probability evaluation methods; Channel models; Simulation or testing of codes
 H03M13/03—Error detection or forward error correction by redundancy in data representation, i.e. code words containing more digits than the source words
 H03M13/05—Error detection or forward error correction by redundancy in data representation, i.e. code words containing more digits than the source words using block codes, i.e. a predetermined number of check bits joined to a predetermined number of information bits
 H03M13/11—Error detection or forward error correction by redundancy in data representation, i.e. code words containing more digits than the source words using block codes, i.e. a predetermined number of check bits joined to a predetermined number of information bits using multiple parity bits
 H03M13/1102—Codes on graphs and decoding on graphs, e.g. lowdensity parity check [LDPC] codes

 H—ELECTRICITY
 H03—BASIC ELECTRONIC CIRCUITRY
 H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
 H03M13/00—Coding, decoding or code conversion, for error detection or error correction; Coding theory basic assumptions; Coding bounds; Error probability evaluation methods; Channel models; Simulation or testing of codes
 H03M13/03—Error detection or forward error correction by redundancy in data representation, i.e. code words containing more digits than the source words
 H03M13/05—Error detection or forward error correction by redundancy in data representation, i.e. code words containing more digits than the source words using block codes, i.e. a predetermined number of check bits joined to a predetermined number of information bits
 H03M13/13—Linear codes
 H03M13/19—Single error correction without using particular properties of the cyclic codes, e.g. Hamming codes, extended or generalised Hamming codes
Abstract
Description
This application claims priority from and is a nonprovisional of U.S. Provisional Patent Application No. 60/775,528 filed Feb. 21, 2006.
The following references are include here and are incorporated by reference for all purposes:
U.S. Pat. No. 6,307,487 entitled “Information Additive Code Generator and Decoder for Communication Systems” issued to Luby (hereinafter “Luby I”);
U.S. Pat. No. 6,320,520 issued to Luby et al. entitled “Information Additive Group Code Generator and Decoder for Communication Systems” (hereinafter “Luby II”);
U.S. Pat. No. 7,068,729 issued to Shokrollahi et al. entitled “MultiStage Code Generator and Decoder for Communication Systems” (hereinafter “Shokrollahi I”);
U.S. Pat. No. 6,909,383 entitled “Systematic Encoding and Decoding of Chain Reaction Codes” issued to Shokrollahi et al. (hereinafter “Shokrollahi II”);
U.S. Pat. No. 6,856,263 entitled “Systems and Processes for Decoding Chain Reaction Codes through Inactivation,” issued to Shokrollahi et al. (hereinafter “Shokrollahi III”); and
U.S. Patent Publication No. 2005/0219070 A1 entitled “Protection of Data from Erasures Using Subsymbol Based Codes” by Shokrollahi, filed Dec. 1, 2004 (hereinafter “Shokrollahi IV”).
The present invention relates to encoding and decoding data in communications systems and more specifically to communication systems that encode and decode data to account for errors and gaps in communicated data. Communication is used in a broad sense, and includes but is not limited to transmission of digital data of any form through space and/or time.
Transmission of files and streams between a sender and a recipient over a communications channel has been the subject of much literature. Preferably, a recipient desires to receive an exact copy of data transmitted over a channel by a sender with some level of certainty. Where the channel does not have perfect fidelity (which covers most all physically realizable systems), one concern is how to deal with data lost or garbled in transmission. Lost data (erasures) are often easier to deal with than corrupted data (errors) because the recipient cannot always tell when corrupted data is data received in error. Many errorcorrecting codes have been developed to correct for erasures and/or for errors. Typically, the particular code used is chosen based on some information about the infidelities of the channel through which the data is being transmitted and the nature of the data being transmitted. For example, where the channel is known to have long periods of infidelity, a burst error code might be best suited for that application. Where only short, infrequent errors are expected a simple parity code might be best.
Data transmission is straightforward when a transmitter and a receiver have all of the computing power and electrical power needed for communications and the channel between the transmitter and receiver is clean enough to allow for relatively errorfree communications. The problem of data transmission becomes more difficult when the channel is in an adverse environment or the transmitter and/or receiver has limited capability.
One solution is the use of forward error correcting (FEC) techniques, wherein data is coded at the transmitter such that a receiver can recover from transmission erasures and errors. Where feasible, a reverse channel from the receiver to the transmitter allows for the receiver to communicate about errors to the transmitter, which can then adjust its transmission process accordingly. Often, however, a reverse channel is not available or feasible or is available only with limited capacity. For example, where the transmitter is transmitting to a large number of receivers, the transmitter might not be able to handle reverse channels from all those receivers. As another example, the communication channel may be a storage medium and thus the transmission of the data is forward through time and, unless someone invents a time travel machine that can go back in time, a reverse channel for this channel is infeasible. As a result, communication protocols often need to be designed without a reverse channel or with a limited capacity reverse channel and, as such, the transmitter may have to deal with widely varying channel conditions without a full view of those channel conditions.
The problem of data transmission between transmitters and receivers is made more difficult when the receivers need to be lowpower, small devices that might be portable or mobile and need to receive data at high bandwidths. For example, a wireless network might be set up to deliver files or streams from a stationary transmitter to a large or indeterminate number of portable or mobile receivers either as a broadcast or multicast where the receivers are constrained in their computing power, memory size, available electrical power, antenna size, device size and other design constraints. Another example is in storage applications where the receiver retrieves data from a storage medium which exhibits infidelities in reproduction of the original data. Such receivers are often embedded with the storage medium itself in devices, for example disk drives, which are highly constrained in terms of computing power and electrical power.
In such a system, considerations to be addressed include having little or no reverse channel, limited memory, limited computing cycles, power, mobility and timing. Preferably, the design should minimize the amount of transmission time needed to deliver data to potentially a large population of receivers, where individual receivers and might be turned on and off at unpredictable times, move in and out of range, incur losses due to link errors, mobility, congestion forcing lower priority file or stream packets to be temporarily dropped, etc.
In the case of a packet protocol used for data transport over a channel that can lose packets, a file, stream or other block of data to be transmitted over a packet network is partitioned into equal size input symbols, encoding symbols the same size as the input symbols are generated from the input symbols using an FEC code, and the encoding symbols are placed and sent in packets. The “size” of a symbol can be measured in bits, whether or not the symbol is actually broken into a bit stream, where a symbol has a size of M bits when the symbol is selected from an alphabet of 2^{M }symbols. In such a packetbased communication system, a packet oriented erasure FEC coding scheme might be suitable. A file transmission is called reliable if it allows the intended recipient to recover an exact copy of the original file even in the face of erasures in the network. A stream transmission is called reliable if it allows the intended recipient to recover an exact copy of each part of the stream in a timely manner even in the face of erasures in the network. Both file transmission and stream transmission can also be somewhat reliable, in the sense that some parts of the file or stream are not recoverable or for streaming if some parts of the stream are not recoverable in a timely fashion. Packet loss often occurs because sporadic congestion causes the buffering mechanism in a router to reach its capacity, forcing it to drop incoming packets. Protection against erasures during transport has been the subject of much study.
In the case of a protocol used for data transmission over a noisy channel that can corrupt bits, a block of data to be transmitted over a data transmission channel is partitioned into equal size input symbols, encoding symbols of the same size are generated from the input symbols and the encoding symbols are sent over the channel. For such a noisy channel the size of a symbol is typically one bit or a few bits, whether or not a symbol is actually broken into a bit stream. In such a communication system, a bitstream oriented errorcorrection FEC coding scheme might be suitable. A data transmission is called reliable if it allows the intended recipient to recover an exact copy of the original block even in the face of errors (symbol corruption, either detected or undetected in the channel). The transmission can also be somewhat reliable, in the sense that some parts of the block may remain corrupted after recovery. Symbols are often corrupted by sporadic noise, periodic noise, interference, weak signal, blockages in the channel, and a variety of other causes. Protection against data corruption during transport has been the subject of much study.
Chain reaction codes are FEC codes that allow for generation of an arbitrary number of output symbols from the fixed input symbols of a file or stream. Sometimes, they are referred to as fountain or rateless FEC codes, since the code does not have an a priori fixed transmission rate. Chain reaction codes have many uses, including the generation of an arbitrary number of output symbols in an information additive way, as opposed to an information duplicative way, wherein the latter is where output symbols received by a receiver before being able to recover the input symbols duplicate already received information and thus do not provide useful information for recovering the input symbols. Novel techniques for generating, using and operating chain reaction codes are shown, for example, in Luby I, Luby II, Shokrollahi I and Shokrollahi II.
One property of the output symbols produced by a chain reaction encoder is that a receiver is able to recover the original file or block of the original stream as soon as enough output symbols have been received. Specifically, to recover the original K input symbols with a high probability, the receiver needs approximately K+A output symbols. The ratio A/K is called the “relative reception overhead.” The relative reception overhead depends on the number K of input symbols, and on the reliability of the decoder.
It is also known to use multistage chain reaction (“MSCR”) codes, such as those described in Shokrollahi I and/or II and developed by Digital Fountain, Inc. under the trade name “Raptor” codes. Multistage chain reaction codes are used, for example, in an encoder that receives input symbols from a source file or source stream, generates intermediate symbols from the input symbols and encodes the intermediate symbols using chain reaction codes. More particularly, a plurality of redundant symbols is generated from an ordered set of input symbols to be communicated. A plurality of output symbols are generated from a combined set of symbols including the input symbols and the redundant symbols, wherein the number of possible output symbols is much larger than the number of symbols in the combined set of symbols, wherein at least one output symbol is generated from more than one symbol in the combined set of symbols and from less than all of the symbols in the combined set of symbols, and such that the ordered set of input symbols can be regenerated to a desired degree of accuracy from any predetermined number, N, of the output symbols. It is also known to use the techniques described above to encode and decode systematic codes, in which the input symbols are includes amongst the possible output symbols of the code. This may be achieved as described in Shokrollahi II by first applying a transformation to the input symbols followed by the steps described above, said enhanced process resulting in the first output symbols generated by the code being equal to the input symbols. As will be clear to those of skill in the art of error and erasure coding, the techniques of Shokrollahi II may be applied directly to the codes described or suggested herein.
For some applications, other variations of codes might be more suitable or otherwise preferred.
The MSCR codes and chain reaction codes described above are extremely efficient in terms of their encoding and decoding complexity. One of the reasons for their efficiency is that the operations that are performed are linear operations over the field GF(2), i.e., the simple field over one bit where the operation of adding two field elements is simply the logical XOR operation, and the operation of multiplying two field elements is simply the logical AND operation. Generally these operations are performed over multiple bits concurrently, e.g., 32 bits at a time or 4 bytes at a time, and such operations are supported natively on all modern CPU processors. On the other hand, when used as erasure FEC codes, because the operations are over GF(2), it turns out that the chance that the receiver can decode all the input symbols goes down by at most approximately onehalf for each additional symbol received beyond the first K, where K is the number of original input symbols. For example, if K+A encoding symbols are received then the chance that the recover process fails to recover the K original input symbols is at least 2^{−A}. What would be a more desirable behavior is if the chance of decoding failure decreased more rapidly as a function of A.
There are other erasure and errorcorrecting FEC codes that operate over larger fields, for example ReedSolomon codes that operate over GF(4), or over GF(8), or over GF(256), or more generally over GF(2^{L}) for any L>1, and also LDPC codes that operate over larger fields. The advantage of such FEC codes is that, for example in the case of erasure FEC codes, the chance of decoding failure decreases much more rapidly as a function of A than FEC codes over GF(2). On the other hand, these FEC codes are typically much less efficient in terms of encoding and decoding complexity, and one of the primary reasons for that is because the operations over larger fields are much more complex and/or are not natively supported on modern CPUs, and the complexity typically grows as the field size grows. Thus, the FEC codes that operate over larger finite fields are often much slower or impractical compared to FEC codes that operate over GF(2).
Thus, what is needed are erasure and errorcorrecting FEC codes that are extremely efficient in terms of their encoding and decoding complexity with the property that the chance of decoding failure decreases very rapidly as a function of the number of symbols received beyond the minimal number needed by an ideal FEC code to recover the original input symbols.
According to one embodiment of the invention, a method of encoding data for transmissions from a source to a destination over a communications channel is provided. The method operates on an ordered set of input symbols and may generate zero or more redundant symbols from the input symbols, each redundant symbol being equal to a linear combination of a number of the input symbols with coefficients taken from one or more finite fields, wherein the finite field used may differ as between different input symbols and between different redundant symbols. The method includes generation of a plurality of output symbols from the combined set of symbols including the input symbols, and the redundant symbols if there are any redundant symbols, wherein each output symbol may be generated from one or more of the combined input and redundant symbols, wherein each output symbol is generated as a linear combination of a number of the input and redundant symbols with coefficients taken from one or more finite fields wherein the finite field used may differ as between different input and redundant symbols, between different output symbols and between the output symbols and the redundant symbols and such that the ordered set of input symbols can be regenerated to a desired degree of accuracy from any predetermined number of the output symbols.
The methods can also be used to generate output symbols, wherein the number of possible output symbols that can be generated from a fixed set of input symbols may be much larger than the number of input symbols.
According to another embodiment of the invention, the method includes receiving at a destination at least some of the output symbols sent from a source over a communications channel, where the transmission over the channel may result in the loss or corruption of some of the sent symbols, and where some of the received symbols may be known to be correctly received and information about the degree of corruption of symbols may also be provided. The method includes regenerating at the destination the ordered set of input symbols to a desired degree of accuracy that depends on how many symbols are received and the knowledge of the corruption of the received symbols.
This embodiment can also include receiving at a destination at least some of the output symbols, wherein the number of possible output symbols that can be received may be much larger than the number of input symbols.
According to another embodiment of the invention, a method of encoding data for transmission from a source to a destination over a communications channel is provided. The method operates on an ordered set of input symbols and includes generating a plurality of redundant symbols from the input symbols. The method also includes generating a plurality of output symbols from a combined set of symbols including the input symbols and the redundant symbols, wherein the operation applied in the generation of output symbols is over a small finite field (for example GF(2)) and such that the ordered set of input symbols can be regenerated to a desired degree of accuracy from any predetermined number of the output symbols. The plurality of redundant symbols is generated from the ordered set of input symbols, wherein the operations to generate the redundant symbols is over a finite field that is not GF(2) (for example, GF(256)) or is over a mix of more than one finite field (for example, some operations over GF(2), some operations over GF(256)).
According to still another embodiment of the invention, a system for receiving data transmitted from a source over a communications channel is provided using similar techniques. The system comprises a receive module coupled to a communications channel for receiving output symbols transmitted over the communications channel, wherein each output symbol is generated from at least one symbol in the combined set of symbols including the input symbols and the redundant symbols, wherein the operation applied in the generation of output symbols is over a small finite field (for example GF(2)) and such that the ordered set of input symbols can be regenerated to a desired degree of accuracy from any predetermined number of the output symbols, wherein the input symbols are from an ordered set of input symbols, wherein the redundant symbols are generated from the input symbols and wherein the plurality of redundant symbols is generated from the ordered set of input symbols, wherein the operations to generate the redundant symbols is over a finite field that is not GF(2) (for example, GF(256)) or is over a mix of more than one finite field (for example, some operations over GF(2), some operations over GF(256)).
According to yet another embodiment of the invention, a computer data signal embodied in a carrier wave is provided.
Numerous benefits are achieved by way of the present invention. For example, in a specific embodiment, the computational expense of encoding data for transmission over a channel is reduced. In another specific embodiment, the computational expense of decoding such data is reduced. In yet another specific embodiment, the error probability of the decoder is reduced, while keeping the computational expense of encoding and decoding low. Depending upon the embodiment, one or more of these benefits may be achieved. These and other benefits are provided in more detail throughout the present specification and more particularly below.
A further understanding of the nature and the advantages of the inventions disclosed herein may be realized by reference to the remaining portions of the specification and the attached drawings.
The detailed description is followed by three appendices: Appendix A contains example values for systematic indices J(K); Appendix B.1 contains example values for table V_{0}; and Appendix B.2 contains example values for table V_{1}.
The inventions described herein make use of mathematical operations for encoding and decoding based on operations in one or more finite fields. Finite fields are finite algebraic structures for which the four arithmetic operations are defined, and which form a field with respect to these operations. Their theory and their construction are well understood by those of skill in the art.
In the description that follows we shall require a multiplication process to be defined between the elements of a finite field and symbols which represent or are derived from the data to be encoded or decoded. Three distinct types of symbols are considered in this description: input symbols comprise information known to the sender which is to be communicated to the receiver, redundant symbols comprise symbols which are derived from the input symbols and output symbols comprise symbols which are transmitted by the sender to the receiver. Of the many possibilities for defining such a multiplication process, we concentrate on two particular ones: simple transformations, and interleaved transformations.
Simple Transformations
In this case, the multiplication process is defined between an element a from a finite field GF(2^{M}) and a symbol S that is M bits in length. As used herein, “symbol” refers to a piece of data that is typically smaller than the source block. The size of a symbol can often be measured in bits, where a symbol has the size of M bits and the symbol is selected from an alphabet of 2^{M }symbols. In applications of reliable transmission of information over packet networks, for example, the size of a symbol could be equal to the packet size, or it could be smaller, so that each packet contains one or more symbols.
In the case of simple transformation, the symbol S is interpreted as an element of GF(2^{M}), and the multiplication a*S is defined as the normal multiplication in the field GF(2^{M}). The operation performed on the symbol is called a “simple transformation” of the symbol. As an illustrative example, consider the field GF(4). Elements of GF(4) can be represented with 2 bits, for example according to their binary expansion. The field GF(4) has four field elements 00, 01, 10, 11, wherein addition is the normal exclusiveor of bit strings, and multiplication is defined via the table:
00  01  10  11  
00  00  00  00  00  
01  00  10  10  11  
10  00  10  11  10  
11  00  11  10  10  
According to the above multiplication table the result of 10*01 would be 10, since 01 is the multiplicative neutral element (sometimes called the identity element) of the field.
Interleaved Transformations
To illustrate interleaved transformations, we will make use of the mathematical concept of a ring. As is wellknown to those of ordinary skill in the art, a ring is a set on which two operations, addition and multiplication, are defined such that these operations satisfy the distributive laws. Moreover, the set considered with addition alone forms an abelian group, i.e., the result of an addition is independent of the ordering of the summands, there is a neutral element 0 for addition, and for each element there is another element such that the sum of these elements is 0. The other requirement is that the multiplication has a neutral element 1, such that multiplication of any element with 1 does not change the value of that element. For a general ring, we do not require that any nonzero element has a multiplicative inverse, nor do we require that multiplication is commutative. When both these conditions are satisfied, however, then we call the ring a “field.” This notation is a standard one in the area of algebra.
A mapping (symbolwise sum) is a logical construct implementable in hardware, software, data storage, etc. that maps pairs of symbols of the same size to another symbol of that size. We denote this mapping by ⊕, and the image of this map on the pair (S,T) of symbols by S⊕T. An example of such a mapping is the bitwise exclusiveor (XOR).
Another construct used here is that of the “action” of a special type of sets on symbols. Suppose that A is a set equipped with a commutative addition operation “+” that has a neutral element and that, for every element, contains its additive inverse. Such a set is also commonly called an abelian group. An “action” of this group on the set of symbols is a mapping that maps a pair, comprising a group element r and a symbol S, to another symbol. We denote the image by r*S where this mapping respects addition in the group, i.e., for every pair of elements a and b in the group A, (a+b)*S=a*S⊕b*S. If A is a ring and the action also respects multiplication in A, where the multiplication operator in A is •, i.e., (a•b)*S=a*(b*S), then this action is the desired multiplication process between elements of a finite field and symbols. In this setting we say that the field “operates” on the set of symbols. The operation performed on symbols in this way is called an “interleaved transformation.”
There are abundant examples of such multiplication processes. A few examples are mentioned below. This list of examples is meant for illustrative purposes only, and should not be considered an exhaustive list, nor should it be construed to limit the scope of this invention.
The field GF(2) with field elements 0 and 1, with addition being exclusiveor (XOR) and multiplication being the logical operation AND, operates on the set of symbols by defining 1*S=S, and 0*S=0, wherein S denotes an arbitrary symbol and 0 denotes the symbol that is entirely zeros.
The field GF(4) can operate on symbols of even size in the following way: for such a symbol S we denote by S[0] and S[1] its first and second half, respectively, so that S=(S[0],S[1]) is the concatenation of S[0] and S[1]. Then, we define
00*S=0
01*S=S
10*S=(S[1], S[0]⊕S[1])
11*S=(S[0]⊕S[1],S[0]).
It can be verified quickly that this is indeed a valid operation. It can be seen that the multiplication table of the field describes an operation that coincides with the operation defined above in the case of 2bit symbols.
Alternatively, the field GF(4) can operate on symbols of even size in the following way: for such a symbol S we denote by S[0] the concatenation of the bits at even positions within S and similarly we denote by S[1] the concatenation of the bits at odd positions within S (where positions are numbered sequentially starting with zero). For two equal length bit strings A and B, let (AB) be defined to be the bit string C of twice the length where the bit in position 2*i of C is the bit in position i of A and the bit in position 2*i+1 of C is the bit in position i+1 of B. Then, we define
00*S=0
01*S=S
10*S=(S[1]S[0]⊕S[1])
11*S=(S[0]⊕S[1]S[0]).
It can be verified quickly that this is indeed a valid operation. It can be seen that all the operations defined above are the same in the case of 2bit symbols.
The interleaved transformations described above can be viewed as a particular case of an interleaved transformation in which the binary length of an element of the field coincides with the length of the symbols in bits, and the operation of field elements on symbols is the same as the multiplication in the finite field.
More generally, if K is an extension field of GF(2) of degree d, then an operation of the field can be defined on symbols whose size is divisible by d. Such an operation is described in the paper “An XORbased erasure resilient coding scheme”, by Bloemer, Kalfane, Karpinksi, Karp, Luby, and Zuckerman, published as Technical Report Number TR95048 of the International Computer Science Institute in Berkeley, 1995. This scheme uses the socalled “regular representation” of the field K as d×d matrices with binary entries.
For these generalizations, the first interleaved transformation partitions S, a string that is d*I bits in length, into d equalsize parts, where the first part S[0] is the first I bits of S, S[1] is the next I bits of S, and S[d−1] is the last I bits of S. The transformation operates on the d parts of S and produces d parts that are concatenated together to form the result of the operation. Alternatively, the second interleaved transformation partitions S into d equalsize parts, where the first part S[0] is the concatenation of each dth bit of S starting at position 0 in S, the second part S[1] is the concatenation of each dth bit of S starting at position 1 in S, the dth part S[d−1] is the concatenation of each dth bit of S starting at position L−1 in S. This second transformation operates on the d parts of S (exactly the same as the first transformation) and produces d parts that are interleaved together to form the result of the operation.
Note that the first interleaved transformation can be computed by XORing consecutive bits of the original string S together, and this is a benefit for software implementations where typically a CPU supports such operations natively. On the other hand, the values of the bits in particular positions in the result of the operation depend on the length of the original string S, and this is somewhat of a disadvantage if one wants to implement the operation in hardware that supports variable length symbols, as the operation of the hardware needs to be different depending on the symbol length. Note that the second interleaved transformation involves XORing nonconsecutive bits of the original string together, and this is somewhat of a disadvantage for software implementations where typically a CPU does not support such XORs as a native operation. Nevertheless, software operations that work on the finite field elements of the symbol directly can be implemented rather efficiently in software, and thus the software implementations of the second interleaved transformation are possible. Furthermore, for the second interleaved transformation the values of the bits in particular positions in the result of the operation does not depend on the length of the original string S, and this is a benefit if one wants to implement the operation in hardware that supports variable length symbols, as the operation of the hardware can be independent of the symbol length. Thus, the second interleaved transformation does have some overall advantages over the first interleaved transformation.
Linear Transformations
The concept of a “linear transformation” can be defined with reference to the simple or interleaved transformations. For given integers m and n, a linear transformation induced by the operation maps vectors of n symbols into vectors of m symbols using the space of matrices with entries in the specified field. A matrix over the field F is a 2dimensional collection of entries, whose entries belong to F. If a matrix has m rows and n columns, then it is commonly referred to as an m×n matrix. The pair (m,n) is called the “format” of the matrix. Matrices of the same format can be added and subtracted, using the addition and subtraction in the underlying field or ring. A matrix of format (m,n) can be multiplied with a matrix of format (n,k) as is commonly known.
In operation, if B denotes a matrix with format (m,n), and B[j/k] denotes the entry of B at position (j,k), and if S denotes the column vector comprising the symbols S_{1}, S_{2}, . . . , S_{n}, and X denotes the column vector comprising the symbols X_{1}, X_{2}, . . . , X_{m}, then the transformation can be expressed as
X=B{circle around (×)}S.
Thus, the following relationship is valid:
for all j from 1 to m, X _{j} =B[j,1]*S _{1} ⊕B[j,2]*S _{2} ⊕ . . . ⊕B[j,n]*S _{n }

 wherein “*” denotes either a simple or an interleaved transformation.
The above formula describes a process for calculating X from B and S in an encoder or decoder, referred to as a “simple transformation process” that can be performed by the steps of:
1. Set j to 1, and X_{j }to 0.
2. For values of k from 1 to n do X_{j}=X_{j}⊕B[j,k]*S_{k}.
3. Increment j by 1. If j is larger than m, then stop, otherwise go to step 2.
Such linear transformations are commonplace in a variety of applications. For example, when using a linear code to encode a piece of data, or source block, S could be the source symbols of the source block to be encoded, X could be the encoded version of S, and B could be a generator matrix for the code. In other applications, for example where the code used is systematic, X could be the redundant symbols of the encoding of S, while B could be the matrix describing the dependency of the redundant symbols on the source symbols.
As will be known to those of skill to in the art, methods are known to perform the operations described above either through the provision of instructions executed within a generalpurpose processor, through hardware designed specifically to perform such operations or through a combination of both. In all cases, the cost of the operations, in terms of the number of instructions required, the amount of hardware required, the cost of the hardware, the electrical power consumed by the operation and/or the time required to perform the operation is generally larger when larger finite fields are used. In particular, in the case of the field GF(2), the operations required are equivalent to bitwise AND and XOR operations which are widely provided within generalpurpose processors and simple, fast and inexpensive to implement in hardware where required. By contrast, operations using larger finite fields than GF(2) are rarely provided directly in generalpurpose processors and require either specialized hardware or a number of processor instructions and memory operations to perform.
MultiField Erasure and Error Correction Codes
Numerous specific embodiments of multifield erasure and error correction codes are described herein by reference to a generalized matrix description. This approach is adopted as a descriptive tool only and does not represent a unique way to describe the embodiments described herein, nor should it be construed to limit the scope of this invention. In the generalized description, a matrix is constructed whose elements are taken from one or more finite fields. Different elements may be taken from different finite fields, with the property that there is a single field in which all the fields can be embedded and specific such embeddings are chosen. Some or all of the output symbols may be identical to some of the input or redundant symbols, or may be distinct from the input and redundant symbols depending on the particular embodiment chosen as will be illustrated further below.
A onetoone correspondence is made between the input symbols of the code and some of the columns of the matrix. A further onetoone correspondence is made between the redundant symbols of the code and the remaining columns of the matrix. Furthermore, a number of rows of the matrix equal to the number of redundant symbols are designated as static rows. Remaining rows of the matrix are designated as dynamic rows. A one to one correspondence is made between the dynamic rows of the matrix and the output symbols of the code. In this description, static rows represent constraints which are required to hold between the input and the redundant symbols and the static rows fully define the relationship between input and redundant symbols such that knowledge of the input symbols and the static rows is sufficient to construct the redundant symbols. Dynamic rows represent the output symbols which are actually sent on the channel. In many codes, the input and/or redundant symbols themselves are sent and this is represented in this description by adding a dynamic row for each input and redundant symbol that is to be transmitted, said dynamic row having a nonzero entry in the column corresponding to the required input or redundant symbol and zero entries in the remaining columns. In some embodiments, the nonzero entry is the identity. In other embodiments, this nonzero entry need not be the identity element.
A matrix of the form described above may be used to determine a method of encoding data for transmission from a source to a destination over a communications channel, the method comprising generating a plurality of redundant symbols from an ordered set of input symbols, wherein each redundant symbol is generated based on a set of linear constraints over one or more of the input symbols and other redundant symbols with coefficients over finite fields, said linear constraints corresponding to the static rows of the matrix description, generating a plurality of output symbols from the combined set of input and redundant symbols, wherein each output symbol is generated as a linear combination of one or more of the combined set of input and redundant symbols with coefficients chosen from finite fields, said linear constraints corresponding to the dynamic rows of the matrix description and sending at least some of the plurality of generated output symbols.
Conversely, a method comprising the above steps may be described in terms of a matrix of the kind described above in which the static rows correspond to the linear constraints over one or more of the input symbols and redundant symbols and the dynamic rows correspond to the linear combinations of the input and redundant symbols which are used to form the output symbols. In practice, embodiments of the method described above may not involve explicit or implicit representation or construction of the matrix described.
As is wellknown, in the case that all elements of the matrix are taken from the field GF(2), then a large class of wellknown errorcorrection and erasurecorrections codes can be described in this way. For example, for the case of LowDensity Parity Check (LDPC) codes, including for example those described in the paper entitled “Design, Evaluation and Comparison of Four Large Block FEC Codecs, LDPC, LDGM, LDGM Staircase and LDGM Triangle, plus a ReedSolomon Small Block FEC Codec” by V. Roca and C. Neumann published as INRIA Research Report RR5225, June 2004, available at www.inrialpes.fr (referred to hereinafter as “Roca”), the generalized matrix can be constructed from the parity check matrix by designating every row of the parity check matrix as a static row and adding a further dynamic row for each input and redundant symbol as described above. Another example might use the singlestage chain reaction codes described in Luby I and Luby II, in which the number of static rows in the matrix is zero and the dynamic rows comprise a standard chain reaction matrix. Another example is the use of MSCR codes, in which case the generalized description here is equivalent to the standard matrix presentation of such codes.
Other codes over larger fields can also be described in this way. For example, ReedSolomon codes such as those derived from Vandermonde matrices in which the input symbols are the source symbols, the generalized matrix is equal to the Vandermonde matrix and all rows are dynamic, where in this case each entry is a finite field element from a field that has at least as many elements in its multiplicative group as there are rows and columns in total, e.g., the finite field GF(256) when the number of rows and columns in total is less than 256. Another example is systematic ReedSolomon codes over a finite field such as GF(256) which are derived from Vandermonde matrices in which case the input symbols are the source symbols, the redundant symbols are the parity symbols, and the matrix is the rows corresponding to the parity symbols within the systematic form of the Vandermonde matrix with all such rows considered static and additional dynamic rows are added for each source and parity symbol as described above since these are exactly the symbols sent over the channel
As is wellknown to those of skill in the art of error and erasure correcting codes, desirable properties of error and erasure correcting include low encoding complexity, low decoding complexity, low decoding error probability and low error floor. The complexity of a code is a measure of the computational resources required to encode or decode the code. Low complexity is of especial value in applications where encoding or decoding is to be performed by resource constrained devices such as mobile terminals, consumer electronics devices, storage devices or devices which may process many encoding or decoding operations simultaneously. Computational complexity is a function in part of the density of the matrix used to encode and decode the code and of the size of the finite field from which the matrix elements are taken. Dense matrices generally result in higher complexity and this has led to many designs of codes based on sparse matrices, for example Low Density Parity Check codes and chain reaction codes. Larger finite fields also result in higher complexity, which has led to many designs of code based on small fields, most commonly GF(2).
Error probability in this context is the probability that completely successful decoding is not possible. Error probability for a given error correcting or erasure correcting code is a function of the information received over the channel, and the specific algorithm used for decoding. In the case of erasure correction codes the error probability is one whenever fewer symbols are received than the number of input symbols. Ideal erasure codes have the property that the error probability is zero whenever the number of symbols received is greater than or equal to the number of input symbols. Other codes have nonzero probability of failure in this case.
It is known that ideal erasure codes can be constructed using dense matrices, in particular ReedSolomon codes. However, in the case of ReedSolomon codes the size of the field required is a function of the code size, which is the sum of the number of input and redundant symbols, and this fact, together with the density of the matrix results in generally high computational complexity, especially as the code size grows. Furthermore, in the case of low density codes, it is known that larger finite fields can be used to reduce error probability for error correction codes (as is demonstrated for example in the paper “Low Density Parity Check Codes over GF(q)” by M. C. Davey and D. J. C. MacKay, which has appeared in the IEEE Communications Letters, volume 2, number 6, pages 165167, 1998) and for erasure codes. Additionally, it is known that introduction of a small number of high density matrix rows or columns into a low density code can improve the error probability, providing a compromise between error probability and complexity [MSCR codes and chain reaction codes]. However, a disadvantage of all such codes is that there is always a significant tradeoff between low complexity and low error probability.
For many FEC codes, i.e., LDPC codes and chain reaction codes and MSRC codes, as more output symbols than the number of input symbols are received, the error probability for successful decoding decreases exponentially at some rate. The error floor of such a code is the error probability at which receipt of additional output symbols decreases the error probability at a much slower rate than when the number of received output symbols first exceeds the number of input symbols. It is known that use of a small number of high density rows or columns and/or the use of a larger finite field for the matrix can result in lower error floor at the cost of higher computational complexity. A disadvantage of many known error and erasure correction codes with low complexity is that the error floor is higher than desirable.
Herein, novel methods are described for construction of error correction and erasure correction codes which address some of the disadvantages mentioned above. Methods for efficient encoding and decoding of such codes are presented with relation to specific embodiments described herein by way of example.
The choice of fields for the matrix elements from a set of more than one possible field as described herein permits the design of codes which retain the low computational complexity of codes over small fields with the low error probability and error floor of codes over larger fields and thus represents a significant advantage over the state of the art.
In one preferred embodiment which will be described in more detail below, for the majority of the rows the entries are chosen from GF(2) and for the remainder of the rows the entries are chosen from GF(256). In another embodiment, for each row exactly one entry is chosen from GF(256) and the remaining elements are chosen from GF(2).
There are many other possible embodiments of use of elements from more than one field that result in an improvement in the tradeoff between computational complexity and error probability and error floor compared to codes known in the art in which all elements are selected from the same field.
As used herein, the term “file” refers to any data that is stored at one or more sources and is to be delivered as a unit to one or more destinations. Thus, a document, an image, and a file from a file server or computer storage device, are all examples of “files” that can be delivered. Files can be of known size (such as a one megabyte image stored on a hard disk) or can be of unknown size (such as a file taken from the output of a streaming source). Either way, the file is a sequence of input symbols, where each input symbol has a position in the file and a value.
As used herein, the term “stream” refers to any data that is stored or generated at one or more sources and is delivered at a specified rate at each point in time in the order it is generated to one or more destinations. Streams can be fixed rate or variable rate. Thus, an MPEG video stream, AMR audio stream, and a data stream used to control a remote device, are all examples of “streams” that can be delivered. The rate of the stream at each point in time can be known (such as 4 megabits per second) or unknown (such as a variable rate stream where the rate at each point in time is not known in advance). Either way, the stream is a sequence of input symbols, where each input symbol has a position in the stream and a value.
Transmission is the process of transmitting data from one or more senders to one or more recipients through a channel in order to deliver a file or stream. A sender is also sometimes referred to as the encoder. If one sender is connected to any number of recipients by a perfect channel, the received data can be an exact copy of the input file or stream, as all the data will be received correctly. Here, we assume that the channel is not perfect, which is the case for most realworld channels. Of the many channel imperfections, two imperfections of interest are data erasure and data incompleteness (which can be treated as a special case of data erasure). Data erasure occurs when the channel loses or drops data. Data incompleteness occurs when a recipient does not start receiving data until some of the data has already passed it by, the recipient stops receiving data before transmission ends, the recipient chooses to only receive a portion of the transmitted data, and/or the recipient intermittently stops and starts again receiving data. As an example of data incompleteness, a moving satellite sender might be transmitting data representing an input file or stream and start the transmission before a recipient is in range. Once the recipient is in range, data can be received until the satellite moves out of range, at which point the recipient can redirect its satellite dish (during which time it is not receiving data) to start receiving the data about the same input file or stream being transmitted by another satellite that has moved into range. As should be apparent from reading this description, data incompleteness is a special case of data erasure, since the recipient can treat the data incompleteness (and the recipient has the same problems) as if the recipient was in range the entire time, but the channel lost all the data up to the point where the recipient started receiving data. Also, as is well known in communication systems design, detectable errors can be considered equivalent to erasures by simply dropping all data blocks or symbols that have detectable errors.
In some communication systems, a recipient receives data generated by multiple senders, or by one sender using multiple connections. For example, to speed up a download, a recipient might simultaneously connect to more than one sender to transmit data concerning the same file. As another example, in a multicast transmission, multiple multicast data streams might be transmitted to allow recipients to connect to one or more of these streams to match the aggregate transmission rate with the bandwidth of the channel connecting them to the sender. In all such cases, a concern is to ensure that all transmitted data is of independent use to a recipient, i.e., that the multiple source data is not redundant among the streams, even when the transmission rates are vastly different for the different streams, and when there are arbitrary patterns of loss.
In general, a communication channel is that which connects the sender and the recipient for data transmission. The communication channel could be a realtime channel, where the channel moves data from the sender to the recipient as the channel gets the data, or the communication channel might be a storage channel that stores some or all of the data in its transit from the sender to the recipient. An example of the latter is disk storage or other storage device. In that example, a program or device that generates data can be thought of as the sender, transmitting the data to a storage device. The recipient is the program or device that reads the data from the storage device. The mechanisms that the sender uses to get the data onto the storage device, the storage device itself and the mechanisms that the recipient uses to get the data from the storage device collectively form the channel. If there is a chance that those mechanisms or the storage device can lose data, then that would be treated as data erasure in the communication channel.
When the sender and recipient are separated by a communication channel in which symbols can be erased, it is preferable not to transmit an exact copy of an input file or stream, but instead to transmit data generated from the input file or stream (which could include all or parts of the input file or stream itself) that assists with recovery of erasures. An encoder is a circuit, device, module or code segment that handles that task. One way of viewing the operation of the encoder is that the encoder generates output symbols from input symbols, where a sequence of input symbol values represents the input file or a block of the stream. Each input symbol would thus have a position, in the input file or block of the stream, and a value. A decoder is a circuit, device, module or code segment that reconstructs the input symbols from the output symbols received by the recipient. In multistage coding, the encoder and the decoder are further divided into submodules each performing a different task.
In embodiments of multistage coding systems, the encoder and the decoder can be further divided into submodules, each performing a different task. For instance, in some embodiments, the encoder comprises what is referred to herein as a static encoder and a dynamic encoder. As used herein, a “static encoder” is an encoder that generates a number of redundant symbols from a set of input symbols, wherein the number of redundant symbols is determined prior to encoding. Examples of static encoding codes include ReedSolomon codes, Tornado codes, Hamming codes, Low Density Parity Check (LDPC) codes, etc. The term “static decoder” is used herein to refer to a decoder that can decode data that was encoded by a static encoder.
As used herein, a “dynamic encoder” is an encoder that generates output symbols from a set of input symbols and possibly a set of redundant symbols. In one preferred embodiment described here, the number of possible output symbols is orders of magnitude larger than the number of input symbols, and the number of output symbols to be generated need not be fixed. One example of such a dynamic encoder is a chain reaction encoder, such as the encoders described in Luby I and Luby II. The term “dynamic decoder” is used herein to refer to a decoder that can decode data that was encoded by a dynamic encoder.
Embodiments of multifield coding need not be limited to any particular type of input symbol. Typically, the values for the input symbols are selected from an alphabet of 2^{M }symbols for some positive integer M. In such cases, an input symbol can be represented by a sequence of M bits of data from the input file or stream. The value of M is often determined based on, for example, the uses of the application, the communication channel, and/or the size of the output symbols. Additionally, the size of an output symbol is often determined based on the application, the channel, and/or the size of the input symbols. In some cases, the coding process might be simplified if the output symbol values and the input symbol values were the same size (i.e., representable by the same number of bits or selected from the same alphabet). If that is the case, then the input symbol value size is limited when the output symbol value size is limited. For example, it may be desired to put output symbols in packets of limited size. If some data about a key associated with the output symbols were to be transmitted in order to recover the key at the receiver, the output symbol would preferably be small enough to accommodate, in one packet, the output symbol value and the data about the key.
As an example, if an input file is a multiple megabyte file, the input file might be broken into thousands, tens of thousands, or hundreds of thousands of input symbols with each input symbol encoding thousands, hundreds, or only few bytes. As another example, for a packetbased Internet channel, a packet with a payload of size of 1024 bytes might be appropriate (a byte is 8 bits). In this example, assuming each packet contains one output symbol and 8 bytes of auxiliary information, an output symbol size of 8128 bits ((1024−8)*8) would be appropriate. Thus, the input symbol size could be chosen as M=(1024−8)*8, or 8128 bits. As another example, some video distribution systems use the MPEG packet standard, where the payload of each packet comprises 188 bytes. In that example, assuming each packet contains one output symbol and 4 bytes of auxiliary information, an output symbol size of 1472 bits ((188−4)*8), would be appropriate. Thus, the input symbol size could be chosen as M=(188−4)*8, or 1472 bits. In a generalpurpose communication system using multistage coding, the applicationspecific parameters, such as the input symbol size (i.e., M, the number of bits encoded by an input symbol), might be variables set by the application.
As another example, for a stream that is sent using variable size source packets, the symbol size might be chosen to be rather small so that each source packet can be covered with an integral number of input symbols that have aggregate size at most slightly larger than the source packet.
Each output symbol has a value. In one preferred embodiment, which we consider below, each output symbol also has associated therewith an identifier called its “key.” Preferably, the key of each output symbol can be easily determined by the recipient to allow the recipient to distinguish one output symbol from other output symbols. Preferably, the key of an output symbol is distinct from the keys of all other output symbols. There are various forms of keying discussed in previous art. For example, Luby I describes various forms of keying that can be employed in embodiments described herein.
Multifield Multistage coding is particularly useful where there is an expectation of data erasure or where the recipient does not begin and end reception exactly when a transmission begins and ends. The latter condition is referred to herein as “data incompleteness.” Regarding erasure events, multistage coding shares many of the benefits of chain reaction coding described in Luby I. In particular, multistage codes may be fountain codes, or rateless codes, in which case many times more distinct output symbols than there are input symbols can be generated for a set of fixedvalue input symbols, and any suitable number of distinct output symbols can be used to recover the input symbols to a desired degree of accuracy. These conditions do not adversely affect the communication process when multifield multistage coding is used, because the output symbols generated with multifield multistage coding are information additive. For example, if a hundred packets are lost due to a burst of noise causing data erasure, an extra hundred packets can be picked up after the burst to replace the loss of the erased packets. If thousands of packets are lost because a receiver did not tune into a transmitter when it began transmitting, the receiver could just pickup those thousands of packets from any other period of transmission, or even from another transmitter. With multifield multistage coding, a receiver is not constrained to pickup any particular set of packets, so it can receive some packets from one transmitter, switch to another transmitter, lose some packets, miss the beginning or end of a given transmission and still recover an input file or block of a stream. The ability to join and leave a transmission without receivertransmitter coordination helps to simplify the communication process.
In some embodiments, transmitting a file or stream using multifield multistage coding can include generating, forming or extracting input symbols from an input file or block of a stream, computing redundant symbols, encoding input and redundant symbols into one or more output symbols, where each output symbol is generated based on its key independently of all other output symbols, and transmitting the output symbols to one or more recipients over a channel. Additionally, in some embodiments, receiving (and reconstructing) a copy of the input file or block of a stream using multifield multistage coding can include receiving some set or subset of output symbols from one of more data streams, and decoding the input symbols from the values and keys of the received output symbols.
Suitable FEC erasure codes as described herein can be used to overcome the abovecited difficulties and would find use in a number of fields including multimedia broadcasting and multicasting systems and services. An FEC erasure code hereafter referred to as “a multifield multistage chain reaction code” has properties that meet many of the current and future requirements of such systems and services.
Some basic properties of multifield multistage chain reaction codes are that, for any packet loss conditions and for delivery of source files of any relevant size or streams of any relevant rate: (a) reception overhead of each individual receiver device (“RD”) is minimized; (b) the total transmission time needed to deliver source files to any number of RDs can be minimized (c) the quality of the delivered stream to any number of RDs can be maximized for the number of output symbols sent relative to the number of input symbols, with suitable selection of transmission schedules. The RDs might be handheld devices, embedded into a vehicle, portable (i.e., movable but not typically in motion when in use) or fixed to a location.
The amount of working memory needed for decoding is low and can still provide the above properties, and the amount of computation needed to encode and decode is minimal. In this document, we provide a simple and easy to implement description of some variations of multifield multistage chain reaction codes.
Multifield Multistage chain reaction codes are fountain codes, i.e., as many encoding packets as needed can be generated onthefly, each containing unique encoding symbols that are equally useful for recovering a source file or block of a stream. There are many advantages to using fountain codes versus other types of FEC codes. One advantage is that, regardless of packet loss conditions and RD availability, fountain codes minimize the number of encoding packets each RD needs to receive to reconstruct a source file or block of a stream. This is true even under harsh packet loss conditions and when, for example, mobile RDs are only intermittently turnedon or available over a long file download session.
Another advantage is the ability to generate exactly as many encoding packets as needed, making the decision on how many encoding packets to generate onthefly while the transmission is in progress. This can be useful if for example there is feedback from RDs indicating whether or not they received enough encoding packets to recover a source file or block of a stream. When packet loss conditions are less severe than expected the transmission can be terminated early. When packet loss conditions are more severe than expected or RDs are unavailable more often than expected the transmission can be seamlessly extended.
Another advantage is the ability to inverse multiplex. Inverse multiplexing is when a RD is able to combine received encoding packets generated at independent senders to reconstruct a source file or block of a stream. One practical use of inverse multiplexing is described in below in reference to receiving encoding packets from different senders.
Where future packet loss, RD availability and application conditions are hard to predict, it is important to choose an FEC solution that is as flexible as possible to work well under unpredictable conditions. Multistage chain reaction codes provide a degree of flexibility unmatched by other types of FEC codes.
A further advantage of multifield multistage codes is that the error probability and error floor of the codes is much lower than those of previously known codes with equivalent computational complexity. Equally, the computational complexity of multifield multistage chain reaction codes is much lower than that of previously known codes with equivalent error probability and/or error floor.
Another advantage of multifield multistage chain reaction codes is that parameters such as symbol size and field sizes can be chosen flexibly to achieve any desired balance between computational complexity and error probability and/or error floor.
Aspects of the invention will now be described with reference to the figures.
System Overview
Static key generator 130 produces a stream of static keys S_{0}, S_{1}, . . . . The number of the static keys generated is generally limited and depends on the specific embodiment of encoder 115. The generation of static keys will be subsequently described in more detail. Dynamic key generator 120 generates a dynamic key for each output symbol to be generated by the encoder 1 15. Each dynamic key is generated so that a large fraction of the dynamic keys for the same input file or block of a stream are unique. For example, Luby I describes embodiments of key generators that can be used. The outputs of dynamic key generator 120 and the static key generator 130 are provided to encoder 115.
From each key I provided by dynamic key generator 120, encoder 115 generates an output symbol, with a value B(I), from the input symbols provided by the input symbol generator. The operation of encoder 115 will be described in more detail below. The value of each output symbol is generated based on its key, on some function of one or more of the input symbols, and possibly on or more redundant symbols that had been computed from the input symbols. The collection of input symbols and redundant symbols that give rise to a specific output symbol is referred to herein as the output symbol's “associated symbols” or just its “associates”. The selection of the function (the “value function”) and the associates is done according to a process described in more detail below. Typically, but not always, M is the same for input symbols and output symbols, i.e., they both code for the same number of bits.
In some embodiments, the number K of input symbols is used by the encoder 115 to select the associates. If K is not known in advance, such as where the input is a streaming file, K can be just an estimate. The value K might also be used by encoder 115 to allocate storage for input symbols and any intermediate symbols generated by encoder 115.
Encoder 115 provides output symbols to a transmit module 140. Transmit module 140 is also provided the key of each such output symbol from the dynamic key generator 120. Transmit module 140 transmits the output symbols, and depending on the keying method used, transmit module 140 might also transmit some data about the keys of the transmitted output symbols, over a channel 145 to a receive module 150. Channel 145 is assumed to be an erasure channel, but that is not a requirement for proper operation of communication system 100. Modules 140, 145 and 150 can be any suitable hardware components, software components, physical media, or any combination thereof, so long as transmit module 140 is adapted to transmit output symbols and any needed data about their keys to channel 145 and receive module 150 is adapted to receive symbols and potentially some data about their keys from channel 145. The value of K, if used to determine the associates, can be sent over channel 145, or it may be set ahead of time by agreement of encoder 115 and decoder 155.
As explained above, channel 145 can be a realtime channel, such as a path through the Internet or a broadcast link from a television transmitter to a television recipient or a telephone connection from one point to another, or channel 145 can be a storage channel, such as a CDROM, disk drive, Web site, or the like. Channel 145 might even be a combination of a realtime channel and a storage channel, such as a channel formed when one person transmits an input file from a personal computer to an Internet Service Provider (ISP) over a telephone line, the input file is stored on a Web server and is subsequently transmitted to a recipient over the Internet.
Because channel 145 is assumed to be an erasure channel, communications system 100 does not assume a onetoone correspondence between the output symbols that exit receive module 150 and the output symbols that go into transmit module 140. In fact, where channel 145 comprises a packet network, communications system 100 might not even be able to assume that the relative order of any two or more packets is preserved in transit through channel 145. Therefore, the key of the output symbols is determined using one or more of the keying schemes described above, and not necessarily determined by the order in which the output symbols exit receive module 150.
Receive module 150 provides the output symbols to a decoder 155, and any data receive module 150 receives about the keys of these output symbols is provided to a dynamic key regenerator 160. Dynamic key regenerator 160 regenerates the dynamic keys for the received output symbols and provides these dynamic keys to decoder 155. Static key generator 163 regenerates the static keys S_{0}, S_{1}, . . . and provides them to decoder 155. The static key generator has access to random number generator 135 used both during the encoding and the decoding process. This can be in the form of access to the same physical device if the random numbers are generated on such device, or in the form of access to the same algorithm for the generation of random numbers to achieve identical behavior. Decoder 155 uses the keys provided by dynamic key regenerator 160 and static key generator 163 together with the corresponding output symbols, to recover the input symbols (again IS(0), IS(1), IS(2), . . . ). Decoder 155 provides the recovered input symbols to an input file reassembler 165, which generates a copy 170 of input file 101 or input stream 105.
One property of the output symbols produced by a chain reaction encoder is that a receiver is able to recover the original file or block of the original stream as soon as enough output symbols have been received. Specifically, to recover the original K input symbols with a high probability, the receiver needs approximately K+A output symbols. The ratio A/K is called the “relative reception overhead.” The relative reception overhead depends on the number K of input symbols, and on the reliability of the decoder. Luby I, Luby II and Shokrollahi I provide teachings of systems and methods that can be employed in certain embodiments. It is to be understood, however, that these systems and methods are not required of the present invention, and many other variations, modifications, or alternatives can also be used.
An Encoder
Dynamic encoder receives the input symbols and the redundant symbols, and generates output symbols as will be described in further detail below. In one embodiment in which the redundant symbols are stored in input symbol buffer 205, dynamic encoder 220 receives the input symbols and redundant symbols from input symbol buffer 205.
Redundancy calculator 230 computes the number R of redundant symbols from the number K of input symbols. This computation is described in further detail below.
Overview of Static Encoder
The general operation of static encoder 210 is shown with reference to
Referring again to
Referring now to
Overview of MultiStage Encoder
Referring again to
Decoder 900 comprises a dynamic decoder 905 and a static decoder 910. Input symbols and redundant symbols recovered by dynamic decoder 905 are stored in a reconstruction buffer 915. Upon completion of dynamic decoding, static decoder 910 attempts to recover any input symbols not recovered by dynamic decoder 905, if any. In particular, static decoder 910 receives input symbols and redundant symbols from reconstruction buffer 915.
In step 1010, dynamic decoder 905 regenerates input symbols and redundant symbols from the Q received output symbols. It is to be understood, that steps 1005 and 1010 can be performed substantially concurrently. For example, dynamic decoder 905 can begin regenerating input symbols and redundant symbols prior to the decoder receiving Q output symbols.
After dynamic decoder 905 has processed Q output symbols, then it is determined whether the input symbols have been recovered to a desired degree of accuracy. The desired degree of accuracy may be, for example, all of the input symbols, or some number, percentage, etc., less than all of the input symbols. If yes, then the flow ends. If no, then the flow proceeds to step 1020. In step 1020, static decoder 910 attempts to recover any input symbols that dynamic decoder 905 was unable to recover. After static encoder 910 has processed the input symbols and redundant symbols recovered by dynamic encoder 905, then the flow ends.
In step 1065, if it is determined that dynamic decoding is not to be stopped, then the flow proceeds back to step 1055. But, if in step 1065, it is determined to end dynamic decoding, then the flow proceeds to step 1070. In step 1070, it is determined whether the input symbols have been recovered to a desired degree of accuracy. If yes, then the flow ends. If no, then the flow proceeds to step 1075. In step 1075, static decoder 910 attempts to recover any input symbols that dynamic decoder 905 was unable to recover. After static encoder 910 has processed the input symbols and redundant symbols recovered by dynamic encoder 905, the flow ends.
Many variations of LDPC decoders and HDPC decoders are well known to those skilled in the art, and can be employed in various embodiments according to the present invention. In one specific embodiment, HDPC decoder is implemented using a Gaussian elimination algorithm. Many variations of Gaussian elimination algorithms are well known to those skilled in the art, and can be employed in various embodiments according to the present invention.
A Variation of HDPC Coding
Another type of HDPC encoding is now described. In this embodiment of HDPC encoding, the mathematical operation for creating redundant symbols from a given set of data is based on operations in a finite field.
In this embodiment of HDPC coding, the elements of a finite field are used to obtain redundant symbols HD[0], . . . , HD[D−1]. These symbols are obtained by defining a multiplication process between the symbols IS[0], . . . ,IS[K−1],LD[0], . . . , LD[E−1] and elements of the finite field as described above.
HDPC Coding
When using an HDPC code, the code might be described by a generator matrix over a finite field GF(2^{M}). Where the code is systematic, which is the case in a preferred embodiment, the generator matrix can be described using only the relationship between the K+E input symbols IS[0], . . . ,IS[K−1],LD[0], . . . ,LD[E−1] and the redundant symbols HD[0], . . . ,HD[D−1]. This matrix, called G, is of format Dx(K+E). If X denotes the column vector comprising the symbols HD[0], . . . ,HD[D−1] and S denotes the column vector comprising the symbols IS[0], . . . ,IS[K−1],LD[0], . . . ,LD[E−1], then we have X=G{circle around (×)}S. More specific embodiments for the matrix G and various methods for efficient computation of the symbols are described below.
Variations
Multistage chain reaction codes as described above are not systematic codes, i.e., all of the original source symbols of a source block are not necessarily among the encoding symbols that are sent. However, systematic FEC codes are useful for a file download system or service, and very important for a streaming system or service. As shown in the implementation below, a modified code can be made to be systematic and still maintain the fountain code and other described properties.
One reason why it is easy to construct a variety of supplemental services using multistage codes is that it can combine received encoding symbols from multiple senders to reconstruct a source file or stream without coordination among the senders. The only requirement is that the senders use differing sets of keys to generate the encoding symbols that they send in encoding packets to the code. Ways to achieve this include designating different ranges of the key space to be used by each such sender, or generating keys randomly at each sender.
As an example of the use of this capability, consider providing a supplemental service to a file download service that allows multistage chain reaction codes that did not receive enough encoding packets to reconstruct a source file from the file download session to request additional encoding packets to be sent from a makeup sender, e.g., via a HTTP session. The makeup sender generates encoding symbols from the source file and sends them, for example using HTTP, and all these encoding symbols can be combined with those received from the file download session to recover the source file. Using this approach allows different senders to provide incremental source file delivery services without coordination between the senders, and ensuring that each individual receiver need receive only a minimal number of encoding packets to recover each source file.
Decoding of multistage chain reaction codes as described above may require a relatively large overhead when the number of source symbols is small, for example in the order of hundreds to a few thousands source symbols. In such a case, a different decoder is preferred, for example a decoder disclosed in Shokrollahi III. As shown in the implementation below, a modified decoding algorithm can be designed for the class of codes disclosed herein that uses features of the codes and concepts disclosed in Shokrollahi III, and provides low decoding error probability for very small numbers of source symbols, while maintaining efficiency in the decoding.
Implementations of Various Stages of MultiField MultiStage Codes
FEC Scheme Definition
A packet using these techniques might be represented with header information such as an FEC Payload ID of four octets comprising a Source Block Number (SBN) (16 bit integer identifier for the source block that the encoding symbols within the packet relate to) and an Encoding Symbol ID (ESI) (16 bit integer identifier for the encoding symbols within the packet). One suitable interpretation of the Source Block Number and Encoding Symbol Identifier is defined in Sections B below. FEC Object Transmission information might comprise the FEC Encoding ID, a Transfer Length (F) and the parameters T, Z, N and A defined in below. The parameters T and Z are 16 bit unsigned integers, N and A are 8 bit unsigned integers. If needed, other integer sizes might be used.
An FEC encoding scheme for forward error correction is defined in the sections below. It defines two different FEC Payload ID formats, one for FEC source packets and another for FEC repair packets, but variations for nonsystematic codes are also possible.
The Source FEC payload ID might comprise a Source Block Number (SBN) (16 bit integer identifier for the source block that the encoding symbols within the packet relate to) and an Encoding Symbol ID (ESI) (16 bit integer identifier for the encoding symbols within the packet), while the Repair FEC Payload ID might comprise a Source Block Number (SBN) (16 bit integer identifier for the source block that the repair symbols within the packet relate to), an Encoding Symbol ID (ESI) (16 bit integer identifier for the repair symbols within the packet), and a Source Block Length (SBL) (16 bits, representing the number of source symbols in the source block. The interpretation of the Source Block Number, Encoding Symbol Identifier and Source Block Length is defined below.
FEC Object Transmission information might comprise the FEC Encoding ID, the maximum source block length, in symbols, and the symbol size, in bytes. The symbol size and maximum source block length might comprise a four octet field of Symbol Size (T) (16 bits representing the size of an encoding symbol, in bytes), and a Maximum Source Block Length (16 bits representing the maximum length of a source block, in symbols).
The sections below specify the systematic multifield MSCR forward error correction code. Multifield MSCR codes are fountain codes, i.e., as many encoding symbols as needed can be generated by the encoder onthefly from the source symbols of a block. The decoder is able to recover the source block from any set of encoding symbols only slightly more in number than the number of source symbols. The code described in this document is a systematic code, that is, the original source symbols are sent unmodified from sender to receiver, as well as a number of repair symbols.
B.1 Definitions, Symbols and Abbreviations
B.1.1 Definitions
For the purposes of this description, the following terms and definitions apply.
 Source block: a block of K source symbols which are considered together for MSCR encoding purposes.
 Source symbol: the smallest unit of data used during the encoding process. All source symbols within a source block have the same size.
 Encoding symbol: a symbol that is included in a data packet. The encoding symbols comprise the source symbols and the repair symbols. Repair symbols generated from a source block have the same size as the source symbols of that source block.
 Systematic code: a code in which the source symbols are included as part of the encoding symbols sent for a source block.
 Repair symbol: the encoding symbols sent for a source block that are not the source symbols. The repair symbols are generated based on the source symbols.
 Intermediate symbols: symbols generated from the source symbols using an inverse encoding process. The repair symbols are then generated directly from the intermediate symbols. The encoding symbols do not include the intermediate symbols, i.e., intermediate symbols are not included in data packets.
 Symbol: a unit of data. The size, in bytes, of a symbol is known as the symbol size.
 Encoding symbol group: a group of encoding symbols that are sent together, i.e., within the same packet whose relationship to the source symbols can be derived from a single Encoding Symbol ID.
 Encoding Symbol ID: information that defines the relationship between the symbols of an encoding symbol group and the source symbols.
 Encoding packet: data packets that contain encoding symbols
 Subblock: a source block is sometime broken into subblocks, each of which is sufficiently small to be decoded in working memory. For a source block comprising K source symbols, each subblock comprises K subsymbols, each symbol of the source block being composed of one subsymbol from each subblock.
 Subsymbol: part of a symbol. Each source symbol is composed of as many subsymbols as there are subblocks in the source block.
 Source packet: data packets that contain source symbols. Repair packet: data packets that contain repair symbols.
B.1.2. Symbols
i, j, x, h, a, b, d,  represent positive integers 
v, m  
ceil(x)  denotes the smallest positive integer which is greater than or equal to x 
choose(i, j)  denotes the number of ways j objects can be chosen from among i objects 
without repetition  
floor(x)  denotes the largest positive integer which is less than or equal to x 
i % j  denotes i modulo j 
X {circumflex over ( )} Y  denotes, for equallength bit strings X and Y, the bitwise exclusiveor of X and 
Y  
A  denote a symbol alignment parameter. Symbol and subsymbol sizes are 
restricted to be multiples of A.  
A^{T}  denotes the transposed matrix of matrix A 
A^{−1}  denotes the inverse matrix of matrix A 
K  denotes the number of symbols in a single source block 
K_{MAX}  denotes the maximum number of source symbols that can be in a single source 
block. Set to 8192. Note that other values might be used.  
L  denotes the number of precoding symbols for a single source block 
S  denotes the number of LDPC symbols for a single source block 
H  denotes the number of Half symbols for a single source block 
C  denotes an array of intermediate symbols, C[0], C[1], C[2], . . . , C[L − 1] 
C′  denotes an array of source symbols, C′[0], C′[1], C′[2], . . . , C′[K − 1] 
X  a nonnegative integer value 
V_{0}, V_{1}  two arrays of 4byte integers, V_{0}[0], V_{0}[1], . . . , V_{0}[255]; V_{1}[0], V_{1}[1], . . . , V_{1}[255] 
Rand[X, i, m]  a pseudorandom number generator 
Deg[ν]  a degree generator 
LTEnc[K, C, (d,  a LT encoding symbol generator 
a, b)]  
Trip[K, X]  a triple generator function 
G  the number of symbols within an encoding symbol group 
N  the number of subblocks within a source block 
T  the symbol size in bytes. If the source block is partitioned into subblocks, 
then T = T′ · N.  
T′  the subsymbol size, in bytes. If the source block is not partitioned into sub 
blocks then T′ is not relevant.  
F  the file size, for file download, in bytes 
I  the subblock size in bytes 
P  for file download, the payload size of each packet, in bytes, that is used in one 
preferred derivation of the file download transport parameters. For streaming,  
the payload size of each repair packet, in bytes, that is used in one preferred  
derivation of the streaming transport parameters.  
Q  Q = 65521, i.e., Q is the largest prime smaller than 2^{16}. Note that other values 
might be used instead of 2^{16}.  
Z  the number of source blocks, for file download 
J(K)  the systematic index associated with K 
G  denotes any generator matrix 
I_{S}  denotes the S × S identity matrix 
0_{S×H}  denotes the S × H zero matrix 
B.1.3 Abbreviations
For the purposes of the present document, the following abbreviations apply:
ESI:  Encoding Symbol ID  
LDPC:  Low Density Parity Check  
LT:  Luby Transform  
SBN:  Source Block Number  
SBL:  Source Block Length (in units of symbols)  
B.2. Overview
The MSCR forward error correction code can be applied to both file delivery and streaming applications. MSCR code aspects which are specific to each of these applications are discussed in Sections B.3 and B.4 of this document.
A component of the systematic MSCR code is the basic encoder described in Section B.5. First, it is described how to derive values for a set of intermediate symbols from the original source symbols such that knowledge of the intermediate symbols is sufficient to reconstruct the source symbols. Secondly, the encoder produces repair symbols which are each the exclusive OR of a number of the intermediate symbols. The encoding symbols are the combination of the source and repair symbols. The repair symbols are produced in such a way that the intermediate symbols and therefore also the source symbols can be recovered from any sufficiently large set of encoding symbols.
This document defines the systematic MSCR code encoder. A number of possible decoding algorithms are possible. An efficient decoding algorithm is provided in Section B.6.
The construction of the intermediate and repair symbols is based in part on a pseudorandom number generator described in Section B.5. This generator is based on a fixed set of 512 random numbers that are available to both sender and receiver. An example set of numbers are those provided in Appendices B.1 and B.2.
Finally, the construction of the intermediate symbols from the source symbols is governed by a “systematic index”. An example set of values for the systematic index is shown in Appendix A for source block sizes from 4 source symbols to K_{MAX}=8192 source symbols.
B.3. File Download
B.3.1. Source Block Construction
B.3.1.1. General
In order to apply the MSCR encoder to a source file, the file may be broken into Z≧1 blocks, known as source blocks. The MSCR encoder is applied independently to each source block. Each source block is identified by a unique integer Source Block Number (SBN), where the first source block has SBN zero, the second has SBN one, etc. Each source block is divided into a number, K, of source symbols of size T bytes each. Each source symbol is identified by a unique integer Encoding Symbol Identifier (ESI), where the first source symbol of a source block has ESI zero, the second has ESI one, etc.
Each source block with K source symbols is divided into N≧1 subblocks, which are small enough to be decoded in the working memory. Each subblock is divided into K subsymbols of size T′.
Note that the value of K is not necessarily the same for each source block of a file and the value of T′ may not necessarily be the same for each subblock of a source block. However, the symbol size T is the same for all source blocks of a file and the number of symbols, K is the same for every subblock of a source block. Exact partitioning of the file into source blocks and subblocks is described in B.3.1.2 below.
B.3.1.2 Source Block and SubBlock Partitioning
The construction of source blocks and subblocks is determined based on five input parameters, F, A, T, Z and N and a function Partition[ ]. The five input parameters are defined as follows:
 F the size of the file, in bytes
 A a symbol alignment parameter, in bytes
 T the symbol size, in bytes, which preferably is a multiple of A
 Z the number of source blocks
 N the number of subblocks in each source block
These parameters might be set so that ceil(ceil(F/T)/Z)≦K_{MAX}. An example of some suitable derivations of these parameters are provided in Section B.3.4.
The function Partition[ ] takes a pair of integers (I, J) as input and derives four integers (I_{L}, I_{S}, J_{L}, J_{S}) as output. Specifically, the value of Partition[I, J] is a sequence of four integers (I_{L}, I_{S}, J_{L}, J_{S}), where I_{L}=ceil(I/J), I_{S}=floor(I/J), J_{L}=I−I_{S}·J and J_{S=J−J} _{L}. Partition[ ] derives parameters for partitioning a block of size I into J approximately equal sized blocks. Specifically, J_{L }blocks of length I_{L }and J_{S }blocks of length I_{S}.
The source file might be partitioned into source blocks and subblocks as follows:
Let,
 K_{t}=ceil(F/T)
 (K_{L}, K_{S}, Z_{L}, Z_{S})=Partition[K_{t},Z]
 (T_{L}, T_{S}, N_{L}, N_{S})=Partition[T/A, N]
Then, the file might be partitioned into Z=Z_{L}+Z_{S }contiguous source blocks, the first Z_{L }source blocks each having length K_{L}·T bytes and the remaining Z_{S }source blocks cach having K_{S}·T bytes.
If K_{t}·T>F then for encoding purposes, the last symbol might be padded at the end with K_{t}·T−F zero bytes.
Next, each source block might be divided into N=N_{L}+N_{S }contiguous subblocks, the first N_{L }subblocks each comprising K contiguous subsymbols of size of T_{L}·A and the remaining N_{S }subblocks each comprising K contiguous subsymbols of size of T_{S}·A. The symbol alignment parameter A ensures that subsymbols are always a multiple of A bytes.
Finally, the mth symbol of a source block comprises the concatenation of the mth subsymbol from each of the N subblocks.
B.3.2. Encoding Packet Construction
B.3.2.1. General
Each encoding packet contains a Source Block Number (SBN), an Encoding Symbol ID (ESI) and encoding symbol(s). Each source block is encoded independently of the others. Source blocks are numbered consecutively from zero. Encoding Symbol ID values from 0 to K−1 identify the source symbols. Encoding Symbol IDs from K onwards identify repair symbols.
B.3.2.2 Encoding Packet Construction
Each encoding packet preferably either contains source symbols (source packet) or contains repair symbols (repair packet). A packet may contain any number of symbols from the same source block. In the case that the last symbol in the packet includes padding bytes added for FEC encoding purposes then these bytes need not be included in the packet. Otherwise, only whole symbols might be included.
The Encoding Symbol ID, X, carried in each source packet is the Encoding Symbol ID of the first source symbol carried in that packet. The subsequent source symbols in the packet have Encoding Symbol IDs, X+1 to X+G−1, in sequential order, where G is the number of symbols in the packet.
Similarly, the Encoding Symbol ID, X, placed into a repair packet is the Encoding Symbol ID of the first repair symbol in the repair packet and the subsequent repair symbols in the packet have Encoding Symbol IDs X+1 to X+G−1 in sequential order, where G is the number of symbols in the packet.
Note that it is not necessary for the receiver to know the total number of repair packets. The G repair symbol triples (d[0], a[0], b[0]), . . . , (d[G−1], a[G−1], b[G−1]) for the repair symbols placed into a repair packet with ESI X are computed using the Triple generator defined in B.5.3.4 as follows:
 For each i=0, . . . , G−1
 (d[i], a[i], b[i])=Trip[K,X+i]
The G repair symbols to be placed in repair packet with ESI X are calculated based on the repair symbol triples as described in Section B.5.3 using the intermediate symbols C and the LT encoder LTenc[K, C, (d[i], a[i], b[i])].
B.3.3. Transport
This section describes the information exchange between the MSCR encoder/decoder and any transport protocol making use of MSCR forward error correction for file delivery.
The MSCR encoder and decoder for file delivery require the following information from the transport protocol: the file size, F, in bytes, the symbol alignment parameter, A, the symbol size, T, in bytes, which is a multiple of A, the number of source blocks, Z, the number of subblocks in each source block, N. The MSCR encoder for file delivery additionally requires the file to be encoded, F bytes.
The MSCR encoder supplies the transport protocol with encoding packet information comprising, for each packet, the SBN, the ESI and the encoding symbol(s). The transport protocol might communicate this information transparently to the MSCR decoder.
B.3.4. Details OF Specific Examples for Parameters
B.3.4.1 Parameter Derivation Algorithm
This section provides examples for the derivation of the four transport parameters, A, T, Z and N that provide good results. These are based on the following input parameters:
 F the file size, in bytes
 W a target on the subblock size, in bytes
 P the maximum packet payload size, in bytes, which is assumed to be a multiple of A
 A the symbol alignment factor, in bytes
 K_{MAX }the maximum number of source symbols per source block.
 K_{MIN }a minimum target on the number of symbols per source block
 G_{MAX }a maximum target number of symbols per packet
Based on the above inputs, the transport parameters T, Z and N are calculated as follows:
Let,
G=min{ceil(P·K _{MIN} /F), P/A, G _{MAX}}−the approximate number of symbols per packet
T=floor(P/(A·G))·A
K _{t}=ceil(F/T)−the total number of symbols in the file
Z=ceil(K _{t} /K _{MAX})
N=min{ceil(ceil(K _{t} /Z)·T/W), T/A}
The values of G and N derived above should be considered as lower bounds. It may be advantageous to increase these values, for example to the nearest power of two. In particular, the above algorithm does not guarantee that the symbol size, T, divides the maximum packet size, P, and so it may not be possible to use the packets of size exactly P. If, instead, G is chosen to be a value which divides P/A, then the symbol size, T, will be a divisor of P and packets of size P can be used.
Suitable values for the input parameters might be W=256 KB, A=4, K_{MIN}=4, and G_{MAX}=1.
B.3.4.2 Examples
The above algorithm leads to transport parameters as shown in
B.4. Streaming
B.4.1. Source Block Construction
A source block is constructed by the transport protocol, for example as defined in this document, making use of the Systematic MSCR Forward Error Correction code. The symbol size, T, to be used for source block construction and the repair symbol construction are provided by the transport protocol. The parameter T might be set so that the number of source symbols in any source block is at most K_{MAX}.
An example of parameters that work well are presented in section B.4.4.
B.4.2. Encoding Packet Construction
As described in B.4.3., each repair packet contains the SBN, ESI, SBL and repair symbol(s). The number of repair symbols contained within a repair packet is computed from the packet length. The ESI values placed into the repair packets and the repair symbol triples used to generate the repair symbols are computed as described in Section B.3.2.2.
B.4.3. Transport
This section describes the information exchange between the MSCR encoder/decoder and any transport protocol making use of MSCR forward error correction for streaming. The MSCR encoder for streaming might use the following information from the transport protocol for each source block: the symbol size, T, in bytes, the number of symbols in the source block, K, the Source Block Number (SBN) and the source symbols to be encoded, K·T bytes. The MSCR encoder supplies the transport protocol with encoding packet information comprising, for each repair packet, the SBN, the ESI, the SBL and the repair symbol(s). The transport protocol might communicate this information transparently to the MSCR decoder.
B.4.4. Selection of Parameters
A number of methods for parameter selection can be used. Some of those are described below in detail.
B.4.4.1 Parameter Derivation Algorithm
This section explains a derivation of the transport parameter T, based on the following input parameters:
B  the maximum source block size, in bytes 
P_{max}  the maximum Source Packet Information size, without padding 
P_{r}  the xth percentile Source Packet Information size, without 
padding (i.e. the least number, n, such that x % of the packets  
are expected to have Source Packet Information size n or less.  
In one embodiment, the value of x is 30.  
A  the symbol alignment factor, in bytes 
K_{MAX}  the maximum number of source symbols per source block. 
K_{MIN}  a minimum target on the number of symbols per source block 
G_{MAX}  a maximum target number of symbols per repair packet 
A requirement on these inputs is that ceil(B/P)≦K_{MAX}. Based on the above inputs, the transport parameter T is calculated as follows:
Let G=min{max{ceil(P·K _{MIN} /B), floor(P _{x} /P _{max})}, P/A, G _{MAX}}−the number of symbols per SPI
T=floor(P/(A·G))·A
The value of T derived above should be considered as a guide to the actual value of T used. It may be advantageous to ensure that T divides into P, or it may be advantageous to set the value of T smaller to minimize wastage when full size repair symbols are used to recover partial source symbols at the end of lost source packets (as long as the maximum number of source symbols in a source block does not exceed K_{MAX}). Furthermore, the choice of T may depend on the source packet size distribution, e.g., if all source packets are the same size then it is advantageous to choose T so that the actual payload size of a repair packet P′, where P′ is a multiple of T, is equal to (or as few bytes as possible larger than) the number of bytes each source packet occupies in the source block.
Suitable values for the input parameters might be A=16, K_{MIN}=4 and G_{MAX}=4.
B.4.4.2 Examples
The above algorithm leads to transport parameters as shown in
B.5. Systematic MultiField MSCR Encoder
B.5.1. Encoding Overview
The systematic MSCR encoder is used to generate repair symbols from a source block that comprises K source symbols.
Symbols are the fundamental data units of the encoding and decoding process. For each source block (subblock) all symbols (subsymbols) are the same size. The atomic operation performed on symbols (subsymbols) for both encoding and decoding is the exclusiveor operation.
 Let C′[0], . . . , C′[K−1] denote the K source symbols.
 Let C′[0], . . . , C′[L−1] denote L intermediate symbols.
The first step of encoding is to generate a number, L>K, of intermediate symbols from the K source symbols. In this step, K source triples (d[0], a[0], b[0]), . . . , (d[K−1], a[K−1], b[K−1]) are generated using the Trip[ ] generator as described in Section B.5.4.4. The K source triples are associated with the K source symbols and are then used to determine the L intermediate symbols C[0], . . . , C[L−1] from the source symbols using an inverse encoding process. This process can be can be realized by a MSCR decoding process.
Certain “precoding relationships” preferably hold within the L intermediate symbols. Section B.5.2 describes these relationships and how the intermediate symbols are generated from the source symbols.
Once the intermediate symbols have been generated, repair symbols are produced and one or more repair symbols are placed as a group into a single data packet. Each repair symbol group is associated with an Encoding Symbol ID (ESI) and a number, G, of encoding symbols. The ESI is used to generate a triple of three integers, (d, a, b) for each repair symbol again using the Trip[ ] generator as described in Section B.5.4.4. This is done as described in Sections B.3 and B.4 using the generators described in Section B.5.4. Then, each (d,a,b)triple is used to generate the corresponding repair symbol from the intermediate symbols using the LTEnc [K, C[0], . . . , C[L−1], (d,a,b)] generator described in Section B.5.4.3.
B.5.2. First Encoding Step: Intermediate Symbol Generation
B.5.2.1 General
The first encoding step is a precoding step to generate the L intermediate symbols C[0], . . . , C[L−1] from the source symbols C′[0], . . . , C′[K−1]. The intermediate symbols are uniquely defined by two sets of constraints:

 1. The intermediate symbols are related to the source symbols by a set of source symbol triples. The generation of the source symbol triples is defined in Section B.5.2.2 using the Trip[ ] generator as described in Section B.5.4.4.
 2. A set of precoding relationships hold within the intermediate symbols themselves.
These are defined in Section B.5.2.3. The generation of the L intermediate symbols is then defined in Section 5.2.4.
B.5.2.2 Source Symbol Triples
Each of the K source symbols is associated with a triple (d[i], a[i], b[i]) for 0≦i<K. The source symbol triples are determined using the Triple generator defined in Section B.5.4.4 as:
 For each i, 0≦i<K
 (d[i], a[i], b[i])=Trip[K, i]
B.5.2.3 PreCoding Relationships
The precoding relationships amongst the L intermediate symbols are defined by expressing the last L−K intermediate symbols in terms of the first K intermediate symbols.
The last L−K intermediate symbols C[K], . . . ,C[L−1] comprise SLDPC symbols and H HDPC symbols The values of S and H are determined from K as described below. Then L=K+S+H.
Let
 X be the smallest positive integer such that X·(X−1)>=2·K.
 S be the smallest prime integer such that S≧ceil(0.01·K)+X
 H be the smallest integer such that choose(H, ceil(H/2))≧K+S
 H′=ceil(H/2)
 L=K+S+H
 C[0], . . . , C[K−1] denote the first K intermediate symbols
 C[K], . . . , C[K+S−1] denote the S LDPC symbols, initialized to zero
 C[K+S], . . . , C[L−1] denote the HHDPC symbols, initialized to zero
The S LDPC symbols are defined to be the values of C[K], . . . , C[K+S−1] at the end of the following process:
 For i=0, . . . , K−1 do
 a=1+(floor(i/S) % (S−1))
 b=i % S
 C[K+b]=C[K+b]^C[i]
 b=(b+a) % S
 C[K+b]=C[K+b]^C[i]
 b=(b+a) % S
 C[K+b]=C[K+b]^C[i]
For the construction of the HHDPC symbols, the system uses the field GF(256). The field can be represented with respect to the irreducible polynomial f=x^{8}+x^{4}+x^{3}+x^{2}+1 over the field GF(2). Let a denote the element x modulo f. As is wellknown to those of ordinary skill in the art, the element a is primitive, i.e., the 255 first powers of a coincide with the 255 nonzero elements of GF(256). In one embodiment, the system choose K+S integers a[0], . . . ,a[K+S−1], and denote by β[0], . . . , β[K+S−1] the elements α^{α[0]}, . . . ,α^{α[K+S−1]}. Further, we choose H further integers b[0], . . . ,b[H−1] and denote by Γ[0], . . . ,Γ[H−1] the elements α^{b[0]}, . . . ,α^{b[H−1]}. Further preferred embodiments of the present invention will specify specific choices for these integers. However, it should be noted that are many equivalent choices of these integers. Let g[i]=i^(floor(i/2)) for all positive integers i. Note that g[i] is the Gray sequence, in which each element differs from the previous one in a single bit position. Furthermore, let g[j,k] denote the j^{th }element,j=0, 1, 2, . . . , of the subsequence of g[i] whose elements have exactly k nonzero bits in their binary representation. As is wellknown to those of skill in the art, the sequence g[j,k] has the property that the binary representations of g[j,k] and g[j+1,k] differ in exactly two positions. We denote these positions by p[j,k,1] and p[j,k,2].
The values of the HDPC symbols are defined as the values of C[K+S], . . . , C[L−1] after the following process.
We initialize a symbol U as 0. The size of this symbol is the same as the common size of source, LDPC, and HDPC symbols.
Next, for a variable h ranging from 0 to K+S−2, we perform the following: The variable U is updated as U=U*β[h]^C[h]. At the same time, we set C[K+S+p[j,H′,1]]=C[K+S+p[j,H′,1]]^U, and C[K+S+p[j,H′,2]]=C[K+S+p[j,H′,2]]^U.
In a further step, we transform U into U*β[K+S−1]^C[K+S−1].
Next, for a variable h ranging from 0 to H−1 we update C[K+S+h]=C[K+S+h]^Γ[h]*U. This completes the description of the HDPC coding process.
In a preferred embodiment, the system chooses the following integers a[0], . . . ,a[K+S−1], and b[0], . . . ,b[H−1]: a[0]=a[1]= . . . =a[K+S−1]=1 and b[0]=1, b[1]=2, . . . b[i]=i+1, etc. Advantageously, in this preferred embodiment, the construction of the HDPC symbols can be performed using only the action of the primitive element, α, along with bitwise exclusive OR operations between symbols. The choice of irreducible polynomial give above admits highly efficient implementation of the action of α, thereby reducing the computational complexity of the HDPC construction algorithm. As will be apparent to those of skill in the art, the construction algorithm described above can easily be adapted to perform the required decoding operations within a multistage code decoder, thus realizing the above mentioned reduction in computational complexity at the decoder as well.
B.5.2.4 Intermediate Symbols
B.5.2.4.1 Definitions
Given the K source symbols C′[0], C′[1], . . . , C′[K−1] the L intermediate symbols C′[0], C[1], . . . , C[L−1] are the uniquely defined symbol values that satisfy the following conditions:

 1. The K source symbols C′[0], C′[1], . . . , C′[K−1] satisfy the K constraints C′[i]=LTEnc[K, (C[0], . . . , C[L−1]), (d[i], a[i], b[i])], for all i, 0≦i<K
 2. The L intermediate symbols C[0], C[1], . . . , C[L−1] satisfy the precoding relationships defined in B.5.2.3.
B.5.2.4.2 Calculation of Intermediate Symbols
This subsection describes a possible method for calculation of the L intermediate symbols C[0], C[1], . . . , C[L−1] satisfying the constraints in B.5.2.4.1
The generator matrix G for a code which generates N output symbols from K input symbols is an N×K matrix over GF(2), where each row corresponds to one of the output symbols and each column to one of the input symbols and where the i^{th }output symbol is equal to the sum of those input symbols whose column contains a nonzero entry in row i.
Then, the L intermediate symbols can be calculated as follows:
Let
 C denote the column vector of the L intermediate symbols, C[0], C[1], . . . , C[L−1].
 D denote the column vector comprising S+H zero symbols followed by the K source symbols C′[0], C′[1], . . . , C′[K−1]
Then the above constraints define an L×L matrix over GF(2), A, such that:
A·C=D
The matrix A can be constructed as follows:
Let:  G_{LDPC }be the S×K generator matrix of the LDPC symbols. So,
 G_{LDPC }(C[0], . . . , C[K−1])^{T}=(C[K], . . . , C[K+S−1])^{T }
 G_{HDPC }be the H×(K+S) generator matrix of the Half symbols, So,
 G_{HDPC}{circle around (×)}(C[0], . . . , C[S+K−1])^{T}=(C[K+S], . . . , C[K+S+H−1])^{T }
 I_{S }be the S×S identity matrix
 I_{H }be the H×H identity matrix
 O_{S×H }be the S×H zero matrix
 G_{LT }be the K×L generator matrix of the encoding symbols generated by the LT Encoder. So,
 G_{LT}·(C[0], . . . , C[L−1])^{T}=(C′[0], C′[1], . . . , C′[K−1])^{T }
 i.e., G_{LTi,j}=1 if and only if C[i] is included in the symbols which are XORed to produce LTEnc[K, (C[0], . . . , C[L−1]), (d[i], a[i], b[i])].
Then:  The first S rows of A are equal to G_{LDPC}I_{S}Z_{S×H}.
 The next H rows of A are equal to G_{HDPC}I_{H}.
 The remaining K rows of A are equal to G_{LT}.
The matrix A is depicted in
C=A ^{−1} ·D
The source triples are generated such that for any K matrix A has full rank and is therefore invertible. This calculation can be realized by applying a MSCR decoding process to the K source symbols C′[0], C′[1], . . . , C′[K−1] to produce the L intermediate symbols C[0], C[1], . . . , C[L−1].
To efficiently generate the intermediate symbols from the source symbols, an efficient decoder implementation such as that described in Section B.6 might be used. The source symbol triples are designed to facilitate efficient decoding of the source symbols using that algorithm.
B.5.3. Second Encoding Step: Chain Reaction Encoding
In the second encoding step, the repair symbol with ESI X is generated by applying the generator LTEnc[K, (C[0], C[1], . . . , C[L−1]), (d, a, b)] defined in Section B.5.4 to the L intermediate symbols C[0], C[1], . . . , C[L−1] using the triple (d, a, b)=Trip[K,X] generated according to Sections B.3.2.2 and B.4.2.
B.5.4. Generators
B.5.4.1 Random Generator
The random number generator Rand[X, i, m] is defined as follows, where X is a nonnegative integer, i is a nonnegative integer and m is a positive integer and the value produced is an integer between 0 and m−1. Let V_{0 }and V_{1 }be arrays of 256 entries each, where each entry is a 4byte unsigned integer. Suitable arrays of random numbers are provided in Appendices B.1 and B.2 by way of example only and should not be construed to limit the scope of the invention. Given those assumptions, Rand[X, i, m]=(V_{0}[(X+i) % 256]^V−_{1}[(floor(X/256)+i) % 256]) % m. As used herein, unless otherwise indicated, “random” should be assumed to include “pseudorandom” and “essentially random”.
B.5.4.2 Degree Generator
The degree generator Deg[v] is defined as follows, where v is an integer that is at least 0 and less than 2^{20}=1048576.
In
 Deg[v]=d[j]
B.5.4.3 Chain Reaction Encoding Symbol Generator
The encoding symbol generator LTEnc[K, (C[0], C[1], . . . , C[L−1]), (d, a, b)] takes the following inputs:
K is the number of source symbols (or subsymbols) for the source block (subblock). Let L be derived from K as described in Section B.5.2, and let L′ be the smallest prime integer greater than or equal to L.
(C[0], C[1], . . . , C[L−1]) is the array of L intermediate symbols (subsymbols) generated as described in Section B.5.2
(d, a, b) is a source triple determined using the Triple generator defined in Section B.5.3.4, whereby d is an integer denoting an encoding symbol degree, a is an integer between 1 and L′−1 inclusive and b is an integer between 0 and L′−1 inclusive.
The encoding symbol generator produces a single encoding symbol as output, according to the following algorithm:
 While (b≧L) do b=(b+a) % L′
 LTEnc[K,(C[0], C[1], . . . , C[L−1]), (d, a, b)]=C[b].
 For j=1, . . . , min(d−1,L−1) do
 b=(b+a) % L′
 While (b≧L) do b=(b+a) % L′
 LTEnc[K, (C[0], C[1], . . . , C[L−1]), (d, a, b)]=LTEnc[K, (C[0], C[1], . . . , C[L−1]), (d, a, b)]^C[b]
B.5.4.4 Triple Generator
The triple generator Trip[K,X] takes the following inputs:
 K The number of source symbols
 X An encoding symbol ID
Let  L be determined from K as described in Section B.5.2
 L′ be the smallest prime that is greater than or equal to L
 Q=65521, the largest prime smaller than 2^{16}.
 J(K) be the systematic index associated with K. The systematic index is a number chosen such that the process below, together which the remaining processed for construction of the matrix A described herein results in a matrix B which is invertible. Suitable systematic indices are provided in Appendix A by way of example only and should not be construed as to limit the scope of the invention.
The output of the triple generator is a triples, (d, a, b) determined as follows:
 1. A=(53591+J(K)·997) % Q
 2. B=10267·(J(K)+1) % Q
 3. Y=(B+X·A) % Q
 4. v=Rand[Y, 0, 2^{20}]
 5. d=Deg[v]
 6. a=1+Rand[Y, 1, L′−1]
 7. b=Rand[Y, 2, L′]
B.6 FEC Decoder Implementations
B.6.1 General
This section describes an efficient decoding algorithm for the MSCR codes described in this specification. Note that each received encoding symbol can be considered as the value of an equation amongst the intermediate symbols. From these simultaneous equations, and the known precoding relationships amongst the intermediate symbols, any algorithm for solving simultaneous equations can successfully decode the intermediate symbols and hence the source symbols. However, the algorithm chosen has a major effect on the computational efficiency of the decoding.
B.6.2 Decoding A Source Block
B.6.2.1 General
It is assumed that the decoder knows the structure of the source block it is to decode, including the symbol size, T, and the number K of symbols in the source block.
From the algorithms described in Sections B.5, the MSCR decoder can calculate the total number L=K+S+H of precoding symbols and determine how they were generated from the source block to be decoded. In this description it is assumed that the received encoding symbols for the source block to be decoded are passed to the decoder. Furthermore, for each such encoding symbol it is assumed that the number and set of intermediate symbols whose exclusiveor is equal to the encoding symbol is passed to the decoder. In the case of source symbols, the source symbol triples described in Section B.5.2.2 indicate the number and set of intermediate symbols which sum to give each source symbol.
Let N≧K be the number of received encoding symbols for a source block and let M=S+H+N. The following M×L matrix A can be derived from the information passed to the decoder for the source block to be decoded. Let C be the column vector of the L intermediate symbols, and let D be the column vector of M symbols with values known to the receiver, where the last S+H of the M symbols are zerovalued symbols that correspond to LDPC and HDPC symbols (these are check symbols for the LDPC and HDPC symbols, and not the LDPC and HDPC symbols themselves), and the remaining N of the M symbols are the received encoding symbols for the source block. Then, A is the matrix that satisfies A·C=D, where here · denotes matrix multiplication over G(256). The matrix A has a block structure, as shown in
Decoding a source block is equivalent to decoding C from known A and D. It is clear that C can be decoded if and only if the rank of A over GF(256) is L. Once C has been decoded, missing source symbols can be obtained by using the source symbol triples to determine the number and set of intermediate symbols which are exclusiveORed to obtain each missing source symbol.
The first step in decoding C is to form a decoding schedule. In this step A is converted, using Gaussian elimination (using row operations and row and column reorderings) and after discarding M−L rows, into the L by L identity matrix. The decoding schedule comprises the sequence of row operations and row and column reorderings during the Gaussian elimination process, and only depends on A and not on D. The decoding of C from D can take place concurrently with the forming of the decoding schedule, or the decoding can take place afterwards based on the decoding schedule.
The correspondence between the decoding schedule and the decoding of C is as follows. Let c[0]=0, c[1]=1 . . . ,c[L−1]=L−1 and d[0]=0, d[1]=1 . . . ,d[M−1]=M−1 initially.
Each time row i of A is exclusiveORed into row i′ in the decoding schedule then in the decoding process symbol D[d[i]] is exclusiveORed into symbol D[d[i′]]. We call this operation a GF(2)row operation.
Each time a multiple α (for some α in GF(256)) of row i of A is exclusiveORed into row i′ in the decoding schedule, then in the decoding process symbol α*D[d[i]] is exclusiveORed into symbol D[d[i′]]. We call this operation a GF(256)row operation. Note that a GF(2)row operation is a particular case of a GF(256)row operation in which the element α is 1.
Each time row i is exchanged with row i′ in the decoding schedule then in the decoding process the value of d[i] is exchanged with the value of d[i′].
Each time column j is exchanged with column j′ in the decoding schedule then in the decoding process the value of c[j] is exchanged with the value of c[j′].
From this correspondence it is clear that the total number of exclusiveORs of symbols in the decoding of the source block is related to the number of row operations (not exchanges) in the Gaussian elimination. Since A is the L by L identity matrix after the Gaussian elimination and after discarding the last M−L rows, it is clear at the end of successful decoding that the L symbols D[d[0]], D[d[0]], . . . , D[d[L−1]] are the values of the L symbols C[c[0]], C[c[1]], . . . , C[c[L−1]].
The order in which Gaussian elimination is performed to form the decoding schedule has no bearing on whether or not the decoding is successful. However, the speed of the decoding depends heavily on the order in which Gaussian elimination is performed. (Furthermore, maintaining a sparse representation of A is crucial, although this is not described here). It is also clear that it is more efficient to perform GF(2)row operations rather than GF(256)row operations. Therefore, when performing the Gaussian elimination, it is better to pivot on rows of the matrix A which with elements taken from the field GF(2). It is also advantageous to leave the elimination of the rows of the matrix corresponding to the HDPC symbols to the end of the Gaussian elimination process. The remainder of this section describes an order in which Gaussian elimination could be performed that is relatively efficient.
B.6.2.2 First Phase
Referring to
The first phase of the Gaussian elimination the matrix X is conceptually partitioned into submatrices. The submatrix sizes are parameterized by nonnegative integers i and u which are initialized to 0. The submatrices of X are:

 (1) The submatrix defined by the intersection of the first i rows and first i columns. This is the identity matrix at the end of each step in the phase.
 (2) The submatrix defined by the intersection of the first i rows and all but the first i columns and last u columns. All entries of this submatrix are zero.
 (3) The submatrix defined by the intersection of the first i columns and all but the first i rows. All entries of this submatrix are zero.
 (4) The submatrix U defined by the intersection of all the rows and the last u columns.
 (5) The submatrix V formed by the intersection of all but the first i columns and the last u columns and all but the first i rows.
There are at most L steps in the first phase. The phase ends when V either disappears or becomes the zero matrix. In each step, a row of X is chosen as follows:
If all entries of V are zero then no row is chosen and the first phase ends.
therwise, let r be the minimum integer such that at least one row of X has exactly r ones in V.
 If r=1, then choose the row with exactly one 1 in V.
 If r=2 then choose any row with exactly 2 ones in V that is part of a maximum size component in the graph defined by Y.
 If r>2 then choose a row with exactly r ones in V with minimum original weight among all such rows.
After the row is chosen in this step the first row of X that intersects V is exchanged with the chosen row so that the chosen row is the first row that intersects V. The columns of X among those that intersect V are reordered so that one of the r ones in the chosen row appears in the first column of V and so that the remaining r−1 ones appear in the last columns of V. Then, the chosen row is exclusiveORed into all the other rows of X below the chosen row that have a one in the first column of V. In other words, we perform a GF(2)row operation in this step. Finally, i is incremented by 1 and u is incremented by r−1, which completes the step.
Let v denote the number of columns of the matrix V at the end of this phase. After permuting the columns of the matrix B so that the columns of V correspond to the last v columns of X, the matrix X will have the form given in
B.6.2.3 Second Phase
We modify the matrix U so it comprises additionally the last v rows of the matrix X, and we replace u accordingly by u+v. The submatrix U is further partitioned into the first i rows, U_{upper}, and the remaining N+S−i rows, U_{lower}, as depicted in
After this step, the matrix A has the form given in
B.6.2.4 Third Place
After the second phase the portions of A which need to be zeroed out to finish converting A into the L by L identity matrix are W and all u columns of U_{upper}, in the case that the first method of zeroing out B_{1 }and B_{2 }has been followed, or W and the last u−s columns of U_{upper}, in the case that the second method of zeroing out B_{1 }and B_{2 }has been followed. In the former case, since the matrix W is generally of small size, it can be zeroed out using elementary GF(2)row operations. After this step, the matrix A has the form given in
The number of rows i′ of the remaining submatrix Û is generally much larger than the number of columns u′. There are several methods which may be used to zero out Û efficiently. In one method, the following precomputation matrix U′ is computed based on, the last u rows and columns of A, which we denote I_{u }and then U′ is used to zero out Û. The u rows of I_{u }are partitioned into ceil(u/z) groups of z rows each, for some integer z. Then, for each group of z rows all nonzero combinations of the z rows are computed, resulting in 2^{z}−1 rows (this can be done with 2^{z}−z−1 exclusiveors of rows per group, since the combinations of Hamming weight one that appear in I_{u }do not need to be recomputed). Thus, the resulting precomputation matrix U′ has ceil(u/z)·2^{z}−1 rows and u columns. Note that U′ is not formally a part of matrix A, but will be used subsequently to zero out U_{upper}. In a preferred embodiment, z=8.
For each of the i′ rows of Û, for each group of z columns in the Û submatrix of this row, if the set of z column entries in Û are not all zero then the row of the precomputation matrix U′ that matches the pattern in the z columns is exclusiveORed into the row, thus zeroing out those z columns in the row at the cost of exclusiveoring one row of U′ into the row.
After this phase A is the L by L identity matrix and a complete decoding schedule has been successfully formed. Then, the corresponding decoding comprising exclusiveORing known encoding symbols can be executed to recover the intermediate symbols based on the decoding schedule.
The triples associated with all source symbols are computed according to B.5.2.2. The triples for received source symbols are used in the decoding. The triples for missing source symbols are used to determine which intermediate symbols need to be exclusiveORed to recover the missing source symbols.
MultiField, SingleStage Chain Reaction Encoders/Decoders
Multifield, singlestage (MFSS) codes have useful properties that are disclosed or suggested herein. Novel arrangements for MFSS codes, encoders and decoders are described herein. In one embodiment, data is encoded for transmission from a source to a destination in which each output symbol is generated as a linear combination of one or more of the input symbols with coefficients taken from finite fields and, for each output symbol:

 selecting according to a random process an integer greater than zero, d, known as the degree of the output symbol,
 selecting according to a random process, a set of size d of input symbols, this set of input symbols to be known as the neighbor set of the output symbol,
 selecting a set of finite fields, such that for at least one output symbol this set contains at least two finite fields,
 selecting for each input symbol in the neighbor set of the output symbol a finite field from the selected set of possible finite fields,
 selecting for each input symbols in the neighbor set of the output symbol, according to a random process, a nonzero element from the finite field selected above.
The random process for selecting the degrees of the output symbols may be a process described in Luby I and Luby II in which the degree is selected according to a degree distribution. The random process for selecting the input symbols to associate with each output symbol may be a process described in Luby I and Luby II in which the input symbols are selected randomly and uniformly. As used herein “random” may include “pseudorandom”, “biased random” and the like.
The set of possible finite fields may be the set {GF(2), GF(256)}.
The process for selecting the finite field may be based on a parameter d_{1}, such that for output symbols of degree less than d_{1}, the field GF(2) is chosen for all input symbols in the neighbor set of the output symbol and for output symbols of degree d_{1 }or greater than the field GF(256) is chosen for at least one, some or all of the members of the neighbor set of the output symbol and the field GF(2) is chosen for the remaining elements of the neighbor set, if any.
The process for selecting the finite field element from the selected field may the simple random process in which an element is chosen uniformly at random from amongst the nonzero elements of the field.
A decoder receiving data encoded by an MFSS encoder as described above might decode the output symbols to regenerate the input symbols by forming a matrix representation of the code according to the method described above, this matrix including no static rows and one dynamic row for each output symbol of the code, and then applying Gaussian Elimination to find the inverse of this matrix, ensuring that at each stage of the Gaussian Elimination process pivot rows of minimal degree are chosen.
As will be clear to those of ordinary skill in the art, many of the wellknown properties of the codes described in Luby I and Luby TI are equally applicable to the codes described above and in particular the choice of an appropriate degree distribution can ensure that with high probability the Gaussian Elimination process is able to identify a row of remaining degree one and thus the decoding process operates as a chain reaction process as described in Luby I and Luby II.
This MFSS code has several further advantages over codes known in the art. Firstly, the inclusion of elements from the field GF(256) reduces significantly the probability that any given received output symbol is not information additive with respect to previously received output symbols. As a result, the decoding error probability of this code is much lower than previous codes. For example, in some instances, the failure probability of the codes described in Luby I and Luby II is improved upon.
An advantage of this code over other codes based on large fields is that output symbols of low degree will generally be processed first by the Gaussian Elimination process and as a result the inclusion of elements from GF(256) need not be considered until later in the decoding process. Since operations over GF(256) are relatively expensive compared to those over GF(2), this results in greatly reduced computational complexity compared to codes where many or all of the symbols are constructed using elements from GF(256) or other large finite fields.
A further advantage over other codes based on large fields is that for those output symbols generated using the larger field, only one element of the neighbor set has a coefficient which is taken from the larger field and as a result only one operation between a symbol and a finite field element is required for each such output symbol. This results in low overall computational complexity.
It is known that using inner codes and outer codes to encode input symbols using two (or more) coding procedures leads to a simple code scheme that provides benefits often found in more complex codes. With the use of inner codes and outer codes, source symbols are first encoded using one of the codes and the output of the first encoder is provided to a coder that codes according to the other code and that result is output as the output symbols. Using an MFSS is, of course, different from the use of inner/outer codes. For one, the output symbols are derived from neighbor sets of input codes. In many of the embodiments described herein, each output symbol is a linear combination of input symbols. With multistage codes, each output symbol might be a linear combination of input symbols and/or redundant and/or intermediate symbols.
Dense MultiField Codes and Encoders/Decoders for Such Codes
In a variation of the teachings described above, the matrix representation of the code is a dense matrix. As is well known, error correction codes can be constructed from dense random matrices over finite fields. For example, a generalized matrix may be constructed in which there are no static rows and each dynamic row comprises elements from GF(2^{q}), with each element chosen randomly. A fixed rate code may then be constructed in which each output symbol corresponds to one of the dynamic rows and is generated as the linear combination of those input symbols for which there is a nonzero element in the corresponding column of this row of the matrix, using these elements as coefficients in the linear combination process.
It is well known to those of skill in the art that the probability that a randomly chosen matrix with K rows and K+A columns with coefficients that are independently and randomly chosen from GF(2^{q}) has a rank that is smaller than K is at most 2^{−qA}. Therefore, the decoding error probability of a code with K input and K/R output symbols in which the output symbols are generated independently and randomly from the input symbols using randomly chosen coefficients from GF(2^{q}) is at most 2^{−qA}, if the number of encoded symbols received is K+A.
In the case of q=1, the code described above has the advantage of reasonable computational complexity, since all operations are within the field GF(2) and thus correspond to conventional XOR operations. However, in this case the lower bound on the failure probability of 2^{−A }once A additional symbols have been received is much higher than desirable.
In the case of q=8, the code described above has the advantage of a lower failure probability (bounded by 2^{−8A }for A additional symbols received). However, in this case all operations are within the field GF(256) and are thus relatively computationally expensive.
A further embodiment allows decoding error probabilities close to those achievable using large values of q to be achieved with computational complexity close to that achievable with small values of q. In this embodiment, output symbols are generated as linear combinations of input symbols with coefficients taken from either GF(2^{q}) or GF(2^{q}) where p<q. In one specific embodiment, exactly (K−2p/q)/R output symbols are generated using coefficients from GF(2^{q}) and the remaining 2p/(qR) output symbols are generated using coefficients from GF(2^{q}).
Data received at a destination can be decoded by determining the linear relationships between received output symbols and the input symbols of the code and solving this set of linear relationships to determine the input symbols.
The decoding error probability of this code is at most that of the code in which all coefficients are chosen from the field GF(2^{p}) and may be significantly lower depending on the number of symbols generated using coefficients from the larger field GF(2^{q}). However, since most of the output symbols are generated using coefficients from GF(2^{p}), the computational complexity of encoding is only slightly greater than that of a code in which all symbols are generated using coefficients from GF(2^{p}). Furthermore, the method of decoding may be so arranged that symbols generated with coefficients form GF(2^{p}) are processed first and thus the majority of the decoding operations are performed with operations exclusively in GF(2^{p}). As a result, the computational complexity of the decoding method is similarly close to that for codes constructed using only GF(2^{p}). In a particular preferred embodiment, p=1 and q=8.
Some Properties of Some MultiField Codes
In most of the examples described above, the input and output symbols encode for the same number of bits and each output symbol is placed in one packet (a packet being a unit of transport that is either received in its entirety or lost in its entirety). In some embodiments, the communications system is modified so that each packet contains several output symbols. The size of an output symbol value is then set to a size determined by the size of the input symbol values in the initial splitting of the file or blocks of the stream into input symbols, based on a number of factors. The decoding process remains essentially unchanged, except that output symbols arrive in bunches as each packet is received.
The setting of input symbol and output symbol sizes is usually dictated by the size of the file or block of the stream and the communication system over which the output symbols are to be transmitted. For example, if a communication system groups bits of data into packets of a defined size or groups bits in other ways, the design of symbol sizes begins with the packet or grouping size. From there, a designer would determine how many output symbols will be carried in one packet or group and that determines the output symbol size. For simplicity, the designer would likely set the input symbol size equal to the output symbol size, but if the input data makes a different input symbol size more convenient, it can be used.
The abovedescribed encoding process produces a stream of packets containing output symbols based on the original file or block of the stream. Each output symbol in the stream is generated independently of all other output symbols, and there is no lower or upper bound on the number of output symbols that can be created. A key is associated with each output symbol. That key, and some contents of the input file or block of the stream, determines the value of the output symbol. Consecutively generated output symbols need not have consecutive keys, and in some applications it would be preferable to randomly generate the sequence of keys, or pseudorandomly generate the sequence.
Multistage decoding has a property that a block of K equalsized input symbols can be recovered from K+A output symbols on average, with very high probability, where A is small compared to K. For example, in the preferred embodiment first described above, when K=100,
Since the particular output symbols are generated in a random or pseudorandom order, and the loss of particular output symbols in transit is generally unrelated to the values of the symbols, there is only a small variance in the actual number of output symbols needed to recover the input file or block. In many cases, where a particular collection of K+A output symbols are not enough to decode the a block, the block is still recoverable if the receiver can receive more output symbols from one or more sources.
Because the number of output symbols is only limited by the resolution of I, well more than K+A output symbols can be generated. For example, if I is a 32bit number, 4 billion different output symbols could be generated, whereas the file or block of the stream could include K=50,000 input symbols. In some applications, only a small number of those 4 billion output symbols may be generated and transmitted and it is a near certainty that an input file or block of a stream can be recovered with a very small fraction of the possible output symbols and an excellent probability that the input file or block can be recovered with slightly more than K output symbols (assuming that the input symbol size is the same as the output symbol size).
In some applications, it may be acceptable to not be able to decode all of the input symbols, or to be able to decode all of input symbols, but with a relatively low probability. In such applications, a receiver can stop attempting to decode all of the input symbols after receiving K+A output symbols. Or, the receiver can stop receiving output symbols after receiving less than K+A output symbols. In some applications, the receiver may even only receive K or less output symbols. Thus, it is to be understood that in some embodiments of the present invention, the desired degree of accuracy need not be complete recovery of all the input symbols.
Further, in some applications where incomplete recovery is acceptable, the data can be encoded such that all of the input symbols cannot be recovered, or such that complete recovery of the input symbols would require reception of many more output symbols than the number of input symbols. Such an encoding would generally require less computational expense, and may thus be an acceptable way to decrease the computational expense of encoding.
It is to be understood that the various functional blocks in the abovedescribed figures may be implemented by a combination of hardware and/or software, and that in specific implementations some or all of the functionality of some of the blocks may be combined. Similarly, it is also to be understood that the various methods described herein may be implemented by a combination of hardware and/or software.
The above description is illustrative and not restrictive. Many variations of the invention will become apparent to those of skill in the art upon review of this disclosure. The scope of the invention should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the appended claims along with their full scope of equivalents.
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Cited By (1)
Publication number  Priority date  Publication date  Assignee  Title 

US20140379858A1 (en) *  20130619  20141225  The Governors Of The University Of Alberta  Network coding using an outer coding process 
Families Citing this family (60)
Publication number  Priority date  Publication date  Assignee  Title 

US6307487B1 (en) *  19980923  20011023  Digital Fountain, Inc.  Information additive code generator and decoder for communication systems 
US20020129159A1 (en) *  20010309  20020912  Michael Luby  Multioutput packet server with independent streams 
US7068729B2 (en) *  20011221  20060627  Digital Fountain, Inc.  Multistage code generator and decoder for communication systems 
US9015564B2 (en)  20090819  20150421  Qualcomm Incorporated  Content delivery system with allocation of source data and repair data among HTTP servers 
US9240810B2 (en)  20020611  20160119  Digital Fountain, Inc.  Systems and processes for decoding chain reaction codes through inactivation 
US9419749B2 (en)  20090819  20160816  Qualcomm Incorporated  Methods and apparatus employing FEC codes with permanent inactivation of symbols for encoding and decoding processes 
ES2459065T3 (en) *  20020611  20140507  Digital Fountain, Inc.  Code decoding chain reaction inactivation 
US9288010B2 (en)  20090819  20160315  Qualcomm Incorporated  Universal file delivery methods for providing unequal error protection and bundled file delivery services 
WO2004034589A9 (en)  20021005  20040715  Digital Fountain Inc  Systematic encoding and decoding of chain reaction codes 
CN1954501B (en)  20031006  20100616  数字方敦股份有限公司  Method for receving data transmitted from a source by communication channel 
KR101161193B1 (en)  20040507  20120702  디지털 파운튼, 인크.  File download and streaming system 
WO2006020826A3 (en) *  20040811  20070802  Digital Fountain Inc  Method and apparatus for fast encoding of data symbols according to halfweight codes 
US9386064B2 (en)  20060609  20160705  Qualcomm Incorporated  Enhanced blockrequest streaming using URL templates and construction rules 
US9432433B2 (en)  20060609  20160830  Qualcomm Incorporated  Enhanced blockrequest streaming system using signaling or block creation 
US9178535B2 (en)  20060609  20151103  Digital Fountain, Inc.  Dynamic stream interleaving and substream based delivery 
US9209934B2 (en)  20060609  20151208  Qualcomm Incorporated  Enhanced blockrequest streaming using cooperative parallel HTTP and forward error correction 
US9380096B2 (en)  20060609  20160628  Qualcomm Incorporated  Enhanced blockrequest streaming system for handling lowlatency streaming 
EP1985021A4 (en)  20060213  20130529  Digital Fountain Inc  Streaming and buffering using variable fec overhead and protection periods 
US9270414B2 (en)  20060221  20160223  Digital Fountain, Inc.  Multiplefield based code generator and decoder for communications systems 
WO2007134196A3 (en)  20060510  20080306  Digital Fountain Inc  Code generator and decoder using hybrid codes 
US8006160B2 (en)  20060629  20110823  Digital Fountain, Inc.  Efficient encoding and decoding methods for representing schedules and processing forward error correction codes 
EP2103022B1 (en) *  20061214  20150429  Thomson Licensing  Rateless codes in communication systems 
US9729274B2 (en)  20061214  20170808  Thomson Licensing  Rateless encoding in communication systems 
WO2008073093A1 (en) *  20061214  20080619  Thomson Licensing  Arq with adaptive modulation for communication systems 
EP2103023B1 (en)  20061214  20150415  Thomson Licensing  Rateless codes decoding method for communication systems 
US9838152B2 (en)  20061214  20171205  Thomson Licensing  Modulation indication method for communication systems 
JP5027305B2 (en)  20070912  20120919  デジタル ファウンテン， インコーポレイテッド  Generation and transmission of the source identification information for enabling reliable communication 
US8370711B2 (en)  20080623  20130205  Ramot At Tel Aviv University Ltd.  Interruption criteria for block decoding 
KR101531184B1 (en) *  20081128  20150624  에스케이 텔레콤주식회사  Decoding method and apparatus and a data transmitting and receiving system by him using a linkage between the upper and lower layer 
GB2454606C (en) *  20090202  20170125  Skype Ltd  Method of transmitting data in a communication system 
US9281847B2 (en)  20090227  20160308  Qualcomm Incorporated  Mobile reception of digital video broadcasting—terrestrial services 
US9298722B2 (en) *  20090716  20160329  Novell, Inc.  Optimal sequential (de)compression of digital data 
WO2013067219A3 (en)  20111101  20130711  Qualcomm Incorporated  Content delivery system with allocation of source data and repair data among http servers 
KR101154818B1 (en) *  20091006  20120608  고려대학교 산학협력단  Decoding method for raptor codes using system 
US20110280311A1 (en)  20100513  20111117  Qualcomm Incorporated  Onestream coding for asymmetric stereo video 
US9485546B2 (en)  20100629  20161101  Qualcomm Incorporated  Signaling video samples for trick mode video representations 
US8918533B2 (en)  20100713  20141223  Qualcomm Incorporated  Video switching for streaming video data 
US9185439B2 (en)  20100715  20151110  Qualcomm Incorporated  Signaling data for multiplexing video components 
US9596447B2 (en)  20100721  20170314  Qualcomm Incorporated  Providing frame packing type information for video coding 
US8806050B2 (en)  20100810  20140812  Qualcomm Incorporated  Manifest file updates for network streaming of coded multimedia data 
US8719657B2 (en) *  20101221  20140506  Industrial Technology Research Institute  Hybrid codec apparatus and method for data transferring 
US8958375B2 (en)  20110211  20150217  Qualcomm Incorporated  Framing for an improved radio link protocol including FEC 
US9270299B2 (en)  20110211  20160223  Qualcomm Incorporated  Encoding and decoding using elastic codes with flexible source block mapping 
US8612842B2 (en) *  20110525  20131217  Infineon Technologies Ag  Apparatus for generating a checksum 
KR101258958B1 (en) *  20110823  20130429  고려대학교 산학협력단  Encoding apparatus and encoding method using raptor codes 
US9253233B2 (en)  20110831  20160202  Qualcomm Incorporated  Switch signaling methods providing improved switching between representations for adaptive HTTP streaming 
US9843844B2 (en)  20111005  20171212  Qualcomm Incorporated  Network streaming of media data 
DE102011115100B3 (en) *  20111007  20121227  Deutsches Zentrum für Luft und Raumfahrt e.V.  Method for restoring lost and/or corrupted data, involves fragmenting output symbols of encoder to fit frame in physical layer, such that received fragments are set as output symbols of parallel encoders 
DE102012200134B4 (en) *  20120105  20130822  Deutsches Zentrum für Luft und Raumfahrt e.V.  A method for transmitting an analog or digital signal 
US8953612B2 (en) *  20120307  20150210  Cmmb Vision Usa Inc  Efficient broadcasting via random linear packet combining 
DE102012203653B3 (en) *  20120308  20130718  Deutsches Zentrum für Luft und Raumfahrt e.V.  Method for restoring lost or damaged data, involves carryingout operations, which are carried on equations that have common equation systems to be solved, once instead of certain times, so that decoding complexity is reduced 
US9294226B2 (en)  20120326  20160322  Qualcomm Incorporated  Universal object delivery and templatebased file delivery 
CN102833051B (en) *  20120824  20141210  北京理工大学  Fountain coding broadcast method based on feedback 
US8839067B2 (en) *  20120831  20140916  Industrial Technology Research Institute  Apparatus and method for accelerating the encoding of raptor codes 
US20140119459A1 (en) *  20121026  20140501  Utsaw Kumar  Enhanced video decoding with application layer forward error correction 
CN103051424B (en) *  20130107  20151118  北京理工大学  One kind of unequal error protection method for wireless transmission of fountain codes 
US20150178163A1 (en) *  20131224  20150625  Industrial Technology Research Institute  System and method for transmitting files 
GB201411503D0 (en) *  20140627  20140813  Norwegian University Of Science And Technology  Galois field coding techniques 
US9590657B2 (en)  20150206  20170307  AlcatelLucent Usa Inc.  Low power lowdensity paritycheck decoding 
US9672030B2 (en) *  20151014  20170606  International Business Machines Corporation  Generating comprehensive symbol tables for source code files 
Citations (550)
Publication number  Priority date  Publication date  Assignee  Title 

US6373406B1 (en)  
US3909721A (en)  19720131  19750930  Signatron  Signal processing system 
US4365338A (en)  19800627  19821221  Harris Corporation  Technique for high rate digital transmission over a dynamic dispersive channel 
US4589112A (en)  19840126  19860513  International Business Machines Corporation  System for multiple error detection with single and double bit error correction 
US4901319A (en)  19880318  19900213  General Electric Company  Transmission system with adaptive interleaving 
US5136592A (en)  19890628  19920804  Digital Equipment Corporation  Error detection and correction system for long burst errors 
US5153591A (en)  19880705  19921006  British Telecommunications Public Limited Company  Method and apparatus for encoding, decoding and transmitting data in compressed form 
US5329369A (en)  19900601  19940712  Thomson Consumer Electronics, Inc.  Asymmetric picture compression 
US5331320A (en)  19911121  19940719  International Business Machines Corporation  Coding method and apparatus using quaternary codes 
US5371532A (en)  19920515  19941206  Bell Communications Research, Inc.  Communications architecture and method for distributing information services 
US5372532A (en)  19930126  19941213  Robertson, Jr.; George W.  Swivel head cap connector 
US5379297A (en)  19920409  19950103  Network Equipment Technologies, Inc.  Concurrent multichannel segmentation and reassembly processors for asynchronous transfer mode 
US5421031A (en)  19890823  19950530  Delta Beta Pty. Ltd.  Program transmission optimisation 
US5425050A (en)  19921023  19950613  Massachusetts Institute Of Technology  Television transmission system using spread spectrum and orthogonal frequencydivision multiplex 
US5432787A (en)  19940324  19950711  Loral Aerospace Corporation  Packet data transmission system with adaptive data recovery method 
JPH07183873A (en)  19931029  19950721  At & T Corp  Information transmitting method for communication system 
EP0669587A2 (en)  19940224  19950830  AT&T Corp.  Networked system for display of multimedia presentations 
US5455823A (en)  19901106  19951003  Radio Satellite Corporation  Integrated communications terminal 
US5465318A (en)  19910328  19951107  Kurzweil Applied Intelligence, Inc.  Method for generating a speech recognition model for a nonvocabulary utterance 
EP0701371A1 (en)  19940908  19960313  International Business Machines Corporation  Video optimised media streamer 
US5517508A (en)  19940126  19960514  Sony Corporation  Method and apparatus for detection and error correction of packetized digital data 
US5524025A (en)  19901107  19960604  At&T Corp.  Coding for digital transmission 
JPH08186570A (en)  19941228  19960716  Toshiba Corp  Error control method in atm network 
US5566208A (en)  19940317  19961015  Philips Electronics North America Corp.  Encoder buffer having an effective size which varies automatically with the channel bitrate 
US5568614A (en)  19940729  19961022  International Business Machines Corporation  Data streaming between peer subsystems of a computer system 
WO1996034463A1 (en)  19950427  19961031  Trustees Of The Stevens Institute Of Technology  High integrity transport for time critical multimedia networking applications 
US5583784A (en)  19930514  19961210  FraunhoferGesellschaft Zur Forderung Der Angewandten Forschung E.V.  Frequency analysis method 
US5608738A (en)  19931110  19970304  Nec Corporation  Packet transmission method and apparatus 
US5617541A (en)  19941221  19970401  International Computer Science Institute  System for packetizing data encoded corresponding to priority levels where reconstructed data corresponds to fractionalized priority level and received fractionalized packets 
US5642365A (en)  19930705  19970624  Mitsubishi Denki Kabushiki Kaisha  Transmitter for encoding error correction codes and a receiver for decoding error correction codes on a transmission frame 
EP0784401A2 (en)  19960112  19970716  Kabushiki Kaisha Toshiba  Digital broadcast receiving terminal apparatus 
US5659614A (en)  19941128  19970819  Bailey, Iii; John E.  Method and system for creating and storing a backup copy of file data stored on a computer 
US5699473A (en)  19951010  19971216  Samsung Electronics Co., Ltd.  Method for recording and reproducing intercoded data using two levels of error correction 
US5701582A (en)  19890823  19971223  Delta Beta Pty. Ltd.  Method and apparatus for efficient transmissions of programs 
WO1997050183A1 (en)  19960625  19971231  Telefonaktiebolaget Lm Ericsson (Publ)  Variable length coding with error protection 
WO1998004973A1 (en)  19960726  19980205  Zenith Electronics Corporation  Data derotator and deinterleaver 
US5751336A (en)  19951012  19980512  International Business Machines Corporation  Permutation based pyramid block transmission scheme for broadcasting in videoondemand storage systems 
US5754563A (en)  19950911  19980519  Ecc Technologies, Inc.  Byteparallel system for implementing reedsolomon errorcorrecting codes 
US5757415A (en)  19940526  19980526  Sony Corporation  Ondemand data transmission by dividing input data into blocks and each block into subblocks such that the subblocks are rearranged for storage to data storage means 
EP0853433A1 (en)  19940824  19980715  Macrovision Corporation  Method and apparatus for detecting a source identification signal in a video signal 
EP0854650A2 (en)  19970117  19980722  NOKIA TECHNOLOGY GmbH  Method for addressing a service in digital video broadcasting 
WO1998032256A1 (en)  19970117  19980723  Telefonaktiebolaget Lm Ericsson (Publ)  Apparatus, and associated method, for transmitting and receiving a multistage, encoded and interleaved digital communication signal 
WO1998032231A1 (en)  19970117  19980723  Qualcomm Incorporated  Method and apparatus for transmitting and receiving concatenated code data 
US5802394A (en)  19940606  19980901  Starlight Networks, Inc.  Method for accessing one or more streams in a video storage system using multiple queues and maintaining continuity thereof 
US5805825A (en)  19950726  19980908  Intel Corporation  Method for semireliable, unidirectional broadcast information services 
US5835165A (en)  19950607  19981110  Lsi Logic Corporation  Reduction of false locking code words in concatenated decoders 
US5844636A (en)  19970513  19981201  Hughes Electronics Corporation  Method and apparatus for receiving and recording digital packet data 
US5852565A (en)  19960130  19981222  Demografx  Temporal and resolution layering in advanced television 
US5870412A (en)  19971212  19990209  3Com Corporation  Forward error correction system for packet based real time media 
JPH1141211A (en)  19970519  19990212  Sanyo Electric Co Ltd  Digital modulatin circuit and its method, and digital demodulation circuit and its method 
EP0903955A1 (en)  19970904  19990324  SGSTHOMSON MICROELECTRONICS S.r.l.  Modular architecture PET decoder for ATM networks 
JPH11112479A (en)  19970717  19990423  Hewlett Packard Co <Hp>  Device and method for ciphering 
US5903775A (en)  19960606  19990511  International Business Machines Corporation  Method for the sequential transmission of compressed video information at varying data rates 
JPH11164270A (en)  19971125  19990618  Kdd  Method and device for transmitting video data using multi channel 
US5917852A (en)  19970611  19990629  L3 Communications Corporation  Data scrambling system and method and communications system incorporating same 
US5926205A (en)  19941019  19990720  Imedia Corporation  Method and apparatus for encoding and formatting data representing a video program to provide multiple overlapping presentations of the video program 
US5933056A (en)  19970715  19990803  Exar Corporation  Single pole current mode commonmode feedback circuit 
US5936949A (en)  19960905  19990810  Netro Corporation  Wireless ATM metropolitan area network 
US5936659A (en)  19960131  19990810  Telcordia Technologies, Inc.  Method for video delivery using pyramid broadcasting 
US5953537A (en)  19930212  19990914  Altera Corporation  Method and apparatus for reducing the number of programmable architecture elements required for implementing a lookup table in a programmable logic device 
US5970098A (en)  19970502  19991019  Globespan Technologies, Inc.  Multilevel encoder 
US6005477A (en)  19970417  19991221  Abb Research Ltd.  Method and apparatus for information transmission via power supply lines 
US6011590A (en)  19970103  20000104  Ncr Corporation  Method of transmitting compressed information to minimize buffer space 
US6012159A (en)  19960117  20000104  Kencast, Inc.  Method and system for errorfree data transfer 
US6014706A (en)  19970130  20000111  Microsoft Corporation  Methods and apparatus for implementing control functions in a streamed video display system 
US6018359A (en)  19980424  20000125  Massachusetts Institute Of Technology  System and method for multicast videoondemand delivery system 
WO2000014921A1 (en)  19980904  20000316  At & T Corp.  Combined channel coding and spaceblock coding in a multiantenna arrangement 
US6041001A (en)  19990225  20000321  Lexar Media, Inc.  Method of increasing data reliability of a flash memory device without compromising compatibility 
EP0986908A1 (en)  19970602  20000322  Northern Telecom Limited  Dynamic selection of media streams for display 
US6044485A (en)  19970103  20000328  Ericsson Inc.  Transmitter method and transmission system using adaptive coding based on channel characteristics 
JP2000151426A (en)  19981117  20000530  Toshiba Corp  Interleave and deinterleave circuit 
US6073250A (en)  19971106  20000606  Luby; Michael G.  Loss resilient decoding technique 
US6079041A (en)  19950804  20000620  Sanyo Electric Co., Ltd.  Digital modulation circuit and digital demodulation circuit 
US6081907A (en)  19970609  20000627  Microsoft Corporation  Data delivery system and method for delivering data and redundant information over a unidirectional network 
US6081918A (en)  19971106  20000627  Spielman; Daniel A.  Loss resilient code with cascading series of redundant layers 
US6081909A (en)  19971106  20000627  Digital Equipment Corporation  Irregularly graphed encoding technique 
US6088330A (en)  19970909  20000711  Bruck; Joshua  Reliable array of distributed computing nodes 
US6097320A (en)  19980120  20000801  Silicon Systems, Inc.  Encoder/decoder system with suppressed error propagation 
EP1024672A1 (en)  19970307  20000802  Sanyo Electric Co., Ltd.  Digital broadcast receiver and display 
JP2000216835A (en)  19990122  20000804  Hitachi Denshi Ltd  Receiver of soft decision decoding system of convolutional code 
WO2000052600A1 (en)  19990303  20000908  Sony Corporation  Transmitter, receiver, transmitter/receiver system, transmission method and reception method 
US6134596A (en)  19970918  20001017  Microsoft Corporation  Continuous media file server system and method for scheduling network resources to play multiple files having different data transmission rates 
US6141053A (en)  19970103  20001031  Saukkonen; Jukka I.  Method of optimizing bandwidth for transmitting compressed video data streams 
US6141787A (en)  19970519  20001031  Sanyo Electric Co., Ltd.  Digital modulation and demodulation 
US6141788A (en)  19980313  20001031  Lucent Technologies Inc.  Method and apparatus for forward error correction in packet networks 
JP2000307435A (en)  19990406  20001102  Internatl Business Mach Corp <Ibm>  Coding circuit, circuit, parity generating method and storage medium 
EP1051027A1 (en)  19990506  20001108  Sony Corporation  Methods and apparatus for data processing, methods and apparatus for data reproducing and recording media 
US6154452A (en)  19990526  20001128  Xm Satellite Radio Inc.  Method and apparatus for continuous crosschannel interleaving 
US6163870A (en)  19971106  20001219  Compaq Computer Corporation  Message encoding with irregular graphing 
JP2000353969A (en)  19990611  20001219  Sony Corp  Receiver for digital voice broadcasting 
US6166544A (en)  19981125  20001226  General Electric Company  MR imaging system with interactive image contrast control 
US6175944B1 (en)  19970715  20010116  Lucent Technologies Inc.  Methods and apparatus for packetizing data for transmission through an erasure broadcast channel 
US6178536B1 (en)  19970814  20010123  International Business Machines Corporation  Coding scheme for file backup and systems based thereon 
US6185265B1 (en)  19980407  20010206  Worldspace Management Corp.  System for time division multiplexing broadcast channels with R1/2 or R3/4 convolutional coding for satellite transmission via onboard baseband processing payload or transparent payload 
JP2001036417A (en)  19990722  20010209  Japan Radio Co Ltd  Device, method and medium for correcting and encoding error, and device, method and medium for decoding error correction code 
US6195777B1 (en)  19971106  20010227  Compaq Computer Corporation  Loss resilient code with double heavy tailed series of redundant layers 
WO2001020786A1 (en)  19990917  20010322  Digital Fountain  Group chain reaction encoder with variable number of associated input data for each output group code 
JP2001094625A (en)  19990927  20010406  Canon Inc  Data communication unit, data communication method and storage medium 
US6223324B1 (en)  19990105  20010424  Agere Systems Guardian Corp.  Multiple program unequal error protection for digital audio broadcasting and other applications 
US6226301B1 (en)  19980219  20010501  Nokia Mobile Phones Ltd  Method and apparatus for segmentation and assembly of data frames for retransmission in a telecommunications system 
US6226259B1 (en)  19970429  20010501  Canon Kabushiki Kaisha  Device and method for transmitting information device and method for processing information 
US6229824B1 (en)  19990526  20010508  Xm Satellite Radio Inc.  Method and apparatus for concatenated convolutional endcoding and interleaving 
US6243846B1 (en)  19971212  20010605  3Com Corporation  Forward error correction system for packet based data and real time media, using crosswise parity calculation 
US6272658B1 (en)  19971027  20010807  Kencast, Inc.  Method and system for reliable broadcasting of data files and streams 
WO2001057667A1 (en)  20000203  20010809  Bandwiz, Inc.  Data streaming 
WO2001058131A2 (en)  20000203  20010809  Bandwiz, Inc.  Broadcast system 
EP1124344A1 (en)  19990820  20010816  Matsushita Electric Industrial Co., Ltd.  Ofdm communication device 
JP2001223655A (en)  19991216  20010817  Lucent Technol Inc  Cluster frame synchronization scheme for satellite digital audio radio system 
US6278716B1 (en)  19980323  20010821  University Of Massachusetts  Multicast with proactive forward error correction 
US20010015944A1 (en)  19970519  20010823  Sony Corporation  Recording method and apparatus for continuous playback of fragmented signals 
JP2001251287A (en)  20000224  20010914  Geneticware Corp Ltd  Confidential transmitting method using hardware protection inside secret key and variable pass code 
US6298462B1 (en)  19970625  20011002  Samsung Electronics Co., Ltd.  Data transmission method for dual diversity systems 
JP2001274855A (en)  20000229  20011005  Koninkl Philips Electronics Nv  Receiver and method for detecting and demodulating received signal subjected to dqpsk modulation and channel encoding 
JP2001274776A (en)  20000324  20011005  Toshiba Corp  Information data transmission system and its transmitter and receiver 
US6307487B1 (en)  19980923  20011023  Digital Fountain, Inc.  Information additive code generator and decoder for communication systems 
US20010033586A1 (en)  19961217  20011025  Satoru Takashimizu  Receiving apparatus for digital broadcasting signal and receving/recording/reproducing apparatus thereof 
US6314289B1 (en)  19981203  20011106  FraunhoferGesellschaft zur Förderung der angewandten Forschung e.V.  Apparatus and method for transmitting information and apparatus and method for receiving information 
US6332163B1 (en)  19990901  20011218  Accenture, Llp  Method for providing communication services over a computer network system 
US6333926B1 (en)  19980811  20011225  Nortel Networks Limited  Multiple user CDMA basestation modem 
US20020009137A1 (en)  20000201  20020124  Nelson John E.  Threedimensional video broadcasting system 
CN1338839A (en)  20000810  20020306  扎尔林克半导体股份有限公司  Codes for combining ReedSolomen and Teb Technologies 
JP2002073625A (en)  20000824  20020312  Nippon Hoso Kyokai <Nhk>  Method server and medium for providing information synchronously with broadcast program 
WO2002027988A2 (en)  20000929  20020404  Visible World, Inc.  System and method for seamless switching 
US20020053062A1 (en)  20000331  20020502  Ted Szymanski  Transmitter, receiver, and coding scheme to increase data rate and decrease bit error rate of an optical data link 
US6393065B1 (en) *  19970829  20020521  Canon Kabushiki Kaisha  Coding and decoding methods and devices and equipment using them 
WO2002047391A1 (en)  20001208  20020613  Digital Fountain, Inc.  Methods and apparatus for scheduling, serving, receiving mediaondemand for clients, servers arranged according to constraints on resources 
US6411223B1 (en)  20001018  20020625  Digital Fountain, Inc.  Generating high weight encoding symbols using a basis 
US20020083345A1 (en)  20000816  20020627  Halliday David C.  Method and system for secure communication over unstable public connections 
US6415326B1 (en)  19980915  20020702  Microsoft Corporation  Timeline correlation between multiple timelinealtered media streams 
US20020085013A1 (en)  20001229  20020704  Lippincott Louis A.  Scan synchronized dual frame buffer graphics subsystem 
US6421387B1 (en)  19980515  20020716  North Carolina State University  Methods and systems for forward error correction based loss recovery for interactive video transmission 
US6420982B1 (en)  20000323  20020716  Mosaid Technologies, Inc.  Multistage lookup for translating between signals of different bit lengths 
JP2002204219A (en)  20001107  20020719  Agere Systems Guardian Corp  Smalldelay communication path code for correcting burst of loss packet 
US6430233B1 (en)  19990830  20020806  Hughes Electronics Corporation  SingleLNB satellite data receiver 
WO2002063461A1 (en)  20010208  20020815  Nokia Corporation  Method and system for buffering streamed data 
US6445717B1 (en)  19980501  20020903  Niwot Networks, Inc.  System for recovering lost information in a data stream 
US20020133247A1 (en)  20001111  20020919  Smith Robert D.  System and method for seamlessly switching between media streams 
US6459811B1 (en)  19980402  20021001  Sarnoff Corporation  Bursty data transmission of compressed video data 
US20020141433A1 (en)  20010330  20021003  Samsung Electronics Co., Ltd.  Apparatus and method for efficiently distributing packet data channel in a mobile communication system for high rate packet transmission 
US20020143953A1 (en)  20010403  20021003  International Business Machines Corporation  Automatic affinity within networks performing workload balancing 
US6466698B1 (en)  19990325  20021015  The United States Of America As Represented By The Secretary Of The Navy  Efficient embedded image and video compression system using lifted wavelets 
US6473010B1 (en)  20000404  20021029  Marvell International, Ltd.  Method and apparatus for determining error correction code failure rate for iterative decoding algorithms 
US6486803B1 (en)  20000922  20021126  Digital Fountain, Inc.  On demand encoding with a window 
US6487692B1 (en)  19991221  20021126  Lsi Logic Corporation  ReedSolomon decoder 
JP2002543705A (en)  19990429  20021217  ノキア コーポレイション  Data transmission 
US6496980B1 (en)  19981207  20021217  Intel Corporation  Method of providing replay on demand for streaming digital multimedia 
US20020191116A1 (en)  20010424  20021219  Damien Kessler  System and data format for providing seamless stream switching in a digital video recorder 
US6497479B1 (en)  20010427  20021224  HewlettPackard Company  Higher organic inks with good reliability and drytime 
US20030005386A1 (en)  20010628  20030102  Sanjay Bhatt  Negotiated/dynamic error correction for streamed media 
JP2003018568A (en)  20010629  20030117  Matsushita Electric Ind Co Ltd  Reproducing system, server apparatus and reproducer 
US6510177B1 (en)  20000324  20030121  Microsoft Corporation  System and method for layered video coding enhancement 
US6523147B1 (en)  19991111  20030218  Ibiquity Digital Corporation  Method and apparatus for forward error correction coding for an AM inband onchannel digital audio broadcasting system 
US20030037299A1 (en)  20010816  20030220  Smith Kenneth Kay  Dynamic variablelength error correction code 
JP2003507985A (en)  19990804  20030225  サン・マイクロシステムズ・インコーポレイテッド  System and method for detecting a 2bit error, to correct the errors due to failures of the components 
JP2003510734A (en)  19990927  20030318  コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ  Files divided for streaming emulate 
US6535920B1 (en)  19990406  20030318  Microsoft Corporation  Analyzing, indexing and seeking of streaming information 
EP1298931A2 (en)  20010920  20030402  Oplayo Oy  Adaptive media stream 
US20030086515A1 (en)  19970731  20030508  Francois Trans  Channel adaptive equalization precoding system and method 
US20030101408A1 (en)  20011129  20030529  Emin Martinian  Apparatus and method for adaptive, multimode decoding 
US20030106014A1 (en)  20011012  20030605  Ralf Dohmen  High speed syndromebased FEC encoder and decoder and system using same 
WO2003046742A1 (en)  20011129  20030605  Nokia Corporation  System and method for identifying and accessing network services 
US6577599B1 (en)  19990630  20030610  Sun Microsystems, Inc.  Smallscale reliable multicasting 
CN1425228A (en)  19991122  20030618  讯捷通讯公司  Variable rate coding for forward link 
JP2003174489A (en)  20011205  20030620  Ntt Docomo Inc  Streaming distribution device and streaming distribution method 
US6584543B2 (en)  19990722  20030624  Micron Technology, Inc.  Reconfigurable memory with selectable error correction storage 
WO2003056703A1 (en)  20011221  20030710  Digital Fountain, Inc.  Multistage code generator and decoder for communication systems 
US20030138043A1 (en)  20020123  20030724  Miska Hannuksela  Grouping of image frames in video coding 
US6609223B1 (en)  19990406  20030819  Kencast, Inc.  Method for packetlevel fec encoding, in which on a source packetbysource packet basis, the error correction contributions of a source packet to a plurality of wildcard packets are computed, and the source packet is transmitted thereafter 
US6618451B1 (en)  19990213  20030909  Altocom Inc  Efficient reduced state maximum likelihood sequence estimator 
JP2003256321A (en)  20020228  20030912  Nec Corp  Proxy server and proxy control program 
KR20030074386A (en)  20020315  20030919  톰슨 라이센싱 소시에떼 아노님  Device and method for inserting error correcting codes and for reconstructing data streams, and corresponding products 
US6631172B1 (en) *  20000501  20031007  Lucent Technologies Inc.  Efficient list decoding of ReedSolomon codes for message recovery in the presence of high noise levels 
US6633856B2 (en)  20010615  20031014  Flarion Technologies, Inc.  Methods and apparatus for decoding LDPC codes 
US20030194211A1 (en)  19981112  20031016  Max Abecassis  Intermittently playing a video 
US6643332B1 (en)  19990709  20031104  Lsi Logic Corporation  Method and apparatus for multilevel coding of digital signals 
US6641366B2 (en)  20010126  20031104  Thorsten Nordhoff  Wind power generating system with an obstruction lighting or night marking device 
US20030207696A1 (en)  20020506  20031106  Serge Willenegger  Multimedia broadcast and multicast service (MBMS) in a wireless communications system 
JP2003319012A (en)  20020419  20031107  Matsushita Electric Ind Co Ltd  Data receiver and data distribution system 
JP2003318975A (en)  20020419  20031107  Matsushita Electric Ind Co Ltd  Data receiving apparatus and data distribution system 
JP2003333577A (en)  20020306  20031121  Hewlett Packard Co <Hp>  Medium streaming distribution system 
US20030224773A1 (en)  20020531  20031204  Douglas Deeds  Fragmented delivery of multimedia 
WO2003105484A1 (en)  20020611  20031218  Telefonaktiebolaget L M Ericsson (Publ)  Generation of mixed media streams 
WO2003105350A1 (en)  20020611  20031218  Digital Fountain, Inc.  Decoding of chain reaction codes through inactivation of recovered symbols 
US6677864B2 (en)  20020418  20040113  Telefonaktiebolaget L.M. Ericsson  Method for multicast over wireless networks 
US6678855B1 (en)  19991202  20040113  Microsoft Corporation  Selecting K in a data transmission carousel using (N,K) forward error correction 
WO2004008735A2 (en)  20020716  20040122  Nokia Corporation  A method for random access and gradual picture refresh in video coding 
JP2004048704A (en)  20020712  20040212  Sumitomo Electric Ind Ltd  Method and device for generating transmission data 
US20040031054A1 (en)  20010104  20040212  Harald Dankworth  Methods in transmission and searching of video information 
US6694476B1 (en)  20000602  20040217  Vitesse Semiconductor Corporation  Reedsolomon encoder and decoder 
WO2004015948A1 (en)  20020813  20040219  Nokia Corporation  Symbol interleaving 
JP2004070712A (en)  20020807  20040304  Nippon Telegr & Teleph Corp <Ntt>  Data delivery method, data delivery system, split delivery data receiving method, split delivery data receiving device and split delivery data receiving program 
WO2004019521A1 (en)  20020731  20040304  Sharp Kabushiki Kaisha  Data communication device, its intermittent communication method, program describing its method, and recording medium on which program is recorded 
US6704370B1 (en)  19981009  20040309  Nortel Networks Limited  Interleaving methodology and apparatus for CDMA 
CN1481643A (en)  20001215  20040310  英国电讯有限公司  Transmission and reception of audio and/or video material 
US20040049793A1 (en)  19981204  20040311  Chou Philip A.  Multimedia presentation latency minimization 
EP1406452A2 (en)  20021003  20040407  NTT DoCoMo, Inc.  Video signal encoding and decoding method 
WO2004030273A1 (en)  20020927  20040408  Fujitsu Limited  Data delivery method, system, transfer method, and program 
WO2004034589A2 (en)  20021005  20040422  Digital Fountain, Inc.  Systematic encoding and decoding of chain reaction codes 
US20040081106A1 (en)  20021025  20040429  Stefan Bruhn  Delay trading between communication links 
WO2004036824A1 (en)  20021014  20040429  Nokia Corporation  Streaming media 
JP2004135013A (en)  20021010  20040430  Matsushita Electric Ind Co Ltd  Device and method for transmission 
US6732325B1 (en)  20001108  20040504  Digeo, Inc.  Errorcorrection with limited working storage 
WO2004040831A1 (en)  20021030  20040513  Koninklijke Philips Electronics N.V.  Adaptative forward error control scheme 
US20040096110A1 (en)  20010420  20040520  Front Porch Digital Inc.  Methods and apparatus for archiving, indexing and accessing audio and video data 
US6742154B1 (en)  20000525  20040525  Ciena Corporation  Forward error correction codes for digital optical network optimization 
JP2004516717A (en)  20001215  20040603  ブリティッシュ・テレコミュニケーションズ・パブリック・リミテッド・カンパニーＢｒｉｔｉｓｈ Ｔｅｌｅｃｏｍｍｕｎｉｃａｔｉｏｎｓ Ｐｕｂｌｉｃ Ｌｉｍｉｔｅｄ Ｃｏｍｐａｎｙ  Audio and, or transmission and reception of video material 
WO2004047455A1 (en)  20021118  20040603  British Telecommunications Public Limited Company  Transmission of video 
WO2004047019A2 (en)  20021121  20040603  Electronics And Telecommunications Research Institute  Encoder using low density parity check codes and encoding method thereof 
US6748441B1 (en)  19991202  20040608  Microsoft Corporation  Data carousel receiving and caching 
JP2004165922A (en)  20021112  20040610  Sony Corp  Apparatus, method, and program for information processing 
US6751772B1 (en)  19990706  20040615  Samsung Electronics Co., Ltd.  Rate matching device and method for a data communication system 
US20040117716A1 (en)  20000920  20040617  Qiang Shen  Single engine turbo decoder with single frame size buffer for interleaving/deinterleaving 
JP2004193992A (en)  20021211  20040708  Sony Corp  Information processing system, information processor, information processing method, recording medium and program 
JP2004192140A (en)  20021209  20040708  Sony Corp  Data communication system, data transmitting device, data receiving device and method, and computer program 
US6765866B1 (en)  20000229  20040720  Mosaid Technologies, Inc.  Link aggregation 
US20040151109A1 (en)  20030130  20040805  Anuj Batra  Timefrequency interleaved orthogonal frequency division multiplexing ultra wide band physical layer 
US20040162071A1 (en)  20030218  20040819  Francesco Grilli  Method and apparatus to track count of broadcast content recipients in a wireless telephone network 
EP1455504A2 (en)  20030307  20040908  Samsung Electronics Co., Ltd.  Apparatus and method for processing audio signal and computer readable recording medium storing computer program for the method 
JP2004529533A (en)  20010216  20040924  ヒューレット・パッカード・カンパニーＨｅｗｌｅｔｔ−Ｐａｃｋａｒｄ Ｃｏｍｐａｎｙ  Method and system for packet communications utilizing the route diversity 
US6804202B1 (en)  19990408  20041012  Lg Information And Communications, Ltd.  Radio protocol for mobile communication system and method 
JP2004289621A (en)  20030324  20041014  Fujitsu Ltd  Data transmission server 
WO2004088988A1 (en)  20030331  20041014  Sharp Kabushiki Kaisha  Video encoder and method of encoding video 
US20040207548A1 (en)  20030421  20041021  Daniel Kilbank  System and method for using a microletbased modem 
US6810499B2 (en)  20000602  20041026  Vitesse Semiconductor Corporation  Product code based forward error correction system 
US6820221B2 (en)  20010413  20041116  HewlettPackard Development Company, L.P.  System and method for detecting process and network failures in a distributed system 
US20040231004A1 (en)  20030513  20041118  Lg Electronics Inc.  HTTP based video streaming apparatus and method in mobile communication system 
JP2004343701A (en)  20030421  20041202  Matsushita Electric Ind Co Ltd  Data receiving reproduction apparatus, data receiving reproduction method, and data receiving reproduction processing program 
JP2004348824A (en)  20030521  20041209  Toshiba Corp  Ecc encoding method and ecc encoding device 
US6831172B1 (en)  19981111  20041214  FarmilaThea Farmaceutici S.P.A.  Crosslinked hyaluronic acids and medical uses thereof 
US20040255328A1 (en)  20030613  20041216  Baldwin James Armand  Fast startup for digital video streams 
WO2004109538A1 (en)  20030607  20041216  Samsung Electronics Co. Ltd.  Apparatus and method for organization and interpretation of multimedia data on a recording medium 
KR20040107152A (en)  20030612  20041220  엘지전자 주식회사  Method for compression/decompression the transferring data of mobile phone 
JP2004362099A (en)  20030603  20041224  Sony Corp  Server device, information processor, information processing method, and computer program 
KR20050009376A (en)  20030716  20050125  삼성전자주식회사  Data recording method with robustness for errors, data reproducing method therefore, and apparatuses therefore 
EP1501318A1 (en)  20020425  20050126  Sharp Corporation  Image encodder, image decoder, record medium, and image recorder 
US6850736B2 (en)  20001221  20050201  Tropian, Inc.  Method and apparatus for reception quality indication in wireless communication 
US6849803B1 (en)  19980115  20050201  Arlington Industries, Inc.  Electrical connector 
US20050028067A1 (en)  20030731  20050203  Weirauch Charles R.  Data with multiple sets of error correction codes 
US20050041736A1 (en)  20030507  20050224  Bernie ButlerSmith  Stereoscopic television signal processing method, transmission system and viewer enhancements 
US20050071491A1 (en)  20030927  20050331  Lg Electronics Inc.  Multimedia streaming service system and method 
US6876623B1 (en)  19981202  20050405  Agere Systems Inc.  Tuning scheme for code division multiplex broadcasting system 
JP2005094140A (en)  20030912  20050407  Sanyo Electric Co Ltd  Video display apparatus 
US6882618B1 (en)  19990907  20050419  Sony Corporation  Transmitting apparatus, receiving apparatus, communication system, transmission method, reception method, and communication method 
WO2005036753A2 (en)  20031006  20050421  Digital Fountain, Inc.  Errorcorrecting multistage code generator and decoder for communication systems having single transmitters or multiple transmitters 
US20050091697A1 (en)  20031027  20050428  Matsushita Electric Industrial Co., Ltd.  Apparatus for receiving broadcast signal 
US20050097213A1 (en)  20031010  20050505  Microsoft Corporation  Architecture for distributed sending of media data 
WO2005041421A1 (en)  20030930  20050506  Telefonaktiebolaget L M Ericsson (Publ)  Inplace data deinterleaving 
US20050102371A1 (en)  20031107  20050512  Emre Aksu  Streaming from a server to a client 
US6895547B2 (en)  20010711  20050517  International Business Machines Corporation  Method and apparatus for low density parity check encoding of data 
US20050105371A1 (en)  19981116  20050519  Johnson Mark G.  Integrated circuit incorporating threedimensional memory array with dual opposing decoder arrangement 
JP2005136546A (en)  20031029  20050526  Sony Corp  Transmission apparatus and method, recording medium, and program 
US20050123058A1 (en)  19990427  20050609  Greenbaum Gary S.  System and method for generating multiple synchronized encoded representations of media data 
US20050138286A1 (en)  20010411  20050623  Franklin Chris R.  Inplace data transformation for faulttolerant disk storage systems 
US20050160272A1 (en)  19991028  20050721  Timecertain, Llc  System and method for providing trusted time in content of digital data files 
JP2005204170A (en)  20040116  20050728  Ntt Docomo Inc  Data receiving apparatus and method 
US20050169379A1 (en)  20040129  20050804  Samsung Electronics Co., Ltd.  Apparatus and method for scalable video coding providing scalability in encoder part 
US6928603B1 (en)  20010719  20050809  Adaptix, Inc.  System and method for interference mitigation using adaptive forward error correction in a wireless RF data transmission system 
JP2005223433A (en)  20040203  20050818  Denso Corp  Streaming data transmitting apparatus and streaming data receiving apparatus 
WO2005078982A1 (en)  20040213  20050825  Nokia Corporation  Identification and retransmission of missing parts 
US6937618B1 (en)  19980520  20050830  Sony Corporation  Separating device and method and signal receiving device and method 
US20050193309A1 (en)  20030821  20050901  Francesco Grilli  Methods for forward error correction coding above a radio link control layer and related apparatus 
US20050195899A1 (en)  20040304  20050908  Samsung Electronics Co., Ltd.  Method and apparatus for video coding, predecoding, and video decoding for video streaming service, and image filtering method 
US20050195900A1 (en)  20040304  20050908  Samsung Electronics Co., Ltd.  Video encoding and decoding methods and systems for video streaming service 
US20050195752A1 (en)  20040308  20050908  Microsoft Corporation  Resolving partial media topologies 
US20050207392A1 (en)  20040319  20050922  Telefonaktiebolaget Lm Ericsson (Publ)  Higher layer packet framing using RLP 
US20050216951A1 (en)  20040326  20050929  Macinnis Alexander G  Anticipatory video signal reception and processing 
US20050216472A1 (en)  20040329  20050929  David Leon  Efficient multicast/broadcast distribution of formatted data 
JP2005277950A (en)  20040325  20051006  Sony Corp  Device and method of transmission, device and method of reception, and program 
US20050219070A1 (en) *  20031201  20051006  Digital Fountain, Inc.  Protection of data from erasures using subsymbol based codes 
US6956875B2 (en)  20020619  20051018  Atlinks Usa, Inc.  Technique for communicating variable bit rate data over a constant bit rate link 
WO2005107123A1 (en)  20040429  20051110  Thomson Licensing Sa  Method of transmitting digital data packets and device implementing the method 
US6965636B1 (en)  20000201  20051115  2Wire, Inc.  System and method for block error correction in packetbased digital communications 
US20050254575A1 (en)  20040512  20051117  Nokia Corporation  Multiple interoperability points for scalable media coding and transmission 
WO2005112250A2 (en)  20040507  20051124  Digital Fountain, Inc.  File download and streaming system 
RU2265960C2 (en)  20030616  20051210  Федеральное государственное унитарное предприятие "Калужский научноисследовательский институт телемеханических устройств"  Method for transferring information with use of adaptive alternation 
CN1714577A (en)  20021118  20051228  英国电讯有限公司  Transmission of video 
US6985459B2 (en)  20020821  20060110  Qualcomm Incorporated  Early transmission and playout of packets in wireless communication systems 
US20060015568A1 (en)  20040714  20060119  Rod Walsh  Grouping of session objects 
US20060020796A1 (en)  20030327  20060126  Microsoft Corporation  Human input security codes 
US6995692B2 (en)  20031014  20060207  Matsushita Electric Industrial Co., Ltd.  Data converter and method thereof 
WO2006013459A1 (en)  20040730  20060209  Nokia Corporation  Pointtopoint repair request mechanism for pointtomultipoint transmission systems 
US20060037057A1 (en)  20040524  20060216  Sharp Laboratories Of America, Inc.  Method and system of enabling trick play modes using HTTP GET 
WO2006020826A2 (en)  20040811  20060223  Digital Fountain, Inc.  Method and apparatus for fast encoding of data symbols according to halfweight codes 
US7010052B2 (en)  20010416  20060307  The Ohio University  Apparatus and method of CTCM encoding and decoding for a digital communication system 
JP2006074421A (en)  20040902  20060316  Sony Corp  Information processor, information recording medium, content management system, and data processing method, and computer program 
JP2006074335A (en)  20040901  20060316  Nippon Telegr & Teleph Corp <Ntt>  Transmission method, transmission system, and transmitter 
WO2006036276A1 (en)  20040721  20060406  Qualcomm Incorporated  Methods and apparatus for providing content information to content servers 
US7031257B1 (en)  20000922  20060418  Lucent Technologies Inc.  Radio link protocol (RLP)/pointtopoint protocol (PPP) design that passes corrupted data and error location information among layers in a wireless data transmission protocol 
JP2006115104A (en)  20041013  20060427  Daiichikosho Co Ltd  Method and device for packetizing timeseries information encoded with high efficiency, and performing realtime streaming transmission, and for reception and reproduction 
US20060093634A1 (en)  20040423  20060504  Lonza Inc.  Personal care compositions and concentrates for making the same 
US20060107174A1 (en)  20041116  20060518  Bernd Heise  Seamless change of depth of a general convolutional interleaver during transmission without loss of data 
US20060109805A1 (en)  20041119  20060525  Nokia Corporation  Packet stream arrangement in multimedia transmission 
WO2006057938A2 (en)  20041122  20060601  Thomson Research Funding Corporation  Method and apparatus for channel change in dsl system 
WO2006060036A1 (en)  20041202  20060608  Thomson Licensing  Adaptive forward error correction 
US20060120464A1 (en)  20020123  20060608  Nokia Corporation  Grouping of image frames in video coding 
EP1670256A2 (en)  20041210  20060614  Microsoft Corporation  A system and process for controlling the coding bit rate of streaming media data 
CN1792056A (en)  20030516  20060621  高通股份有限公司  Reliable reception of broadcast/multicast content 
US7068681B2 (en)  19990510  20060627  Samsung Electronics Co., Ltd.  Apparatus and method for exchanging variablelength data according to radio link protocol in mobile communication system 
JP2006174045A (en)  20041215  20060629  Ntt Communications Kk  Image distribution device, program, and method therefor 
JP2006174032A (en)  20041215  20060629  Sanyo Electric Co Ltd  Image data transmission system, image data receiver and image data transmitter 
US7073191B2 (en)  20000408  20060704  Sun Microsystems, Inc  Streaming a single media track to multiple clients 
US7072971B2 (en)  20001113  20060704  Digital Foundation, Inc.  Scheduling of multiple files for serving on a server 
JP2006186419A (en)  20041224  20060713  Daiichikosho Co Ltd  Device for transmitting/receiving and reproducing time series information encoded with high efficiency by real time streaming 
CN1806392A (en)  20040120  20060719  三星电子株式会社  Apparatus and method for generating and decoding forward error correction codes having variable rate in a highrate wireless data communication system 
WO2006084503A1 (en)  20050208  20060817  Telefonaktiebolaget Lm Ericsson (Publ)  Ondemand multichannel streaming session over packetswitched networks 
US7100188B2 (en)  19990526  20060829  Enounce, Inc.  Method and apparatus for controlling timescale modification during multimedia broadcasts 
US20060193524A1 (en)  20050218  20060831  Tetsu Tarumoto  Image display method, image coding apparatus, and image decoding apparatus 
US7110412B2 (en)  20010918  20060919  Sbc Technology Resources, Inc.  Method and system to transport highquality video signals 
US20060212444A1 (en)  20010516  20060921  Pandora Media, Inc.  Methods and systems for utilizing contextual feedback to generate and modify playlists 
US20060212782A1 (en) *  20050315  20060921  Microsoft Corporation  Efficient implementation of reedsolomon erasure resilient codes in highrate applications 
US20060229075A1 (en)  20050409  20061012  Lg Electronics Inc.  Supporting handover of mobile terminal 
JP2006287422A (en)  20050331  20061019  Brother Ind Ltd  Distribution rate control apparatus, distribution system, distribution rate control method, and distribution rate control program 
WO2006116102A2 (en)  20050428  20061102  Qualcomm Incorporated  Multicarrier operation in data transmission systems 
US20060244865A1 (en)  20050302  20061102  Rohde & Schwarz, Inc.  Apparatus, systems, methods and computer products for providing a virtual enhanced training sequence 
US20060248195A1 (en)  20050427  20061102  Kunihiko Toumura  Computer system with a packet transfer device using a hash value for transferring a content request 
US20060244824A1 (en)  19890823  20061102  Debey Henry C  Method and system of program transmission optimization using a redundant transmission sequence 
US20060256851A1 (en)  20050413  20061116  Nokia Corporation  Coding, storage and signalling of scalability information 
US7139660B2 (en)  20040714  20061121  General Motors Corporation  System and method for changing motor vehicle personalization settings 
CN1868157A (en)  20030821  20061122  高通股份有限公司  Methods for forward error correction coding above a radio link control layer and related apparatus 
US20060262856A1 (en)  20050520  20061123  Microsoft Corporation  Multiview video coding based on temporal and view decomposition 
JP2006319743A (en)  20050513  20061124  Toshiba Corp  Receiving device 
US7143433B1 (en)  20001227  20061128  Infovalve Computing Inc.  Video distribution system using dynamic segmenting of video data files 
US20060279437A1 (en)  20050610  20061214  Digital Fountain, Inc.  Forward errorcorrecting (fec) coding and streaming 
US7151754B1 (en)  20000922  20061219  Lucent Technologies Inc.  Complete user datagram protocol (CUDP) for wireless multimedia packet networks using improved packet level forward error correction (FEC) coding 
WO2006135878A2 (en)  20050610  20061221  Digital Fountain, Inc.  Inplace transformations with applications to encoding and decoding various classes of codes 
US7154951B2 (en)  19970314  20061226  Microsoft Corporation  Motion video signal encoder and encoding method 
RU2290768C1 (en)  20060130  20061227  Общество с ограниченной ответственностью "Трафиклэнд"  Media broadcast system in infrastructure of mobile communications operator 
US20070006274A1 (en)  20050630  20070104  Toni Paila  Transmission and reception of session packets 
US20070002953A1 (en)  20050629  20070104  Kabushiki Kaisha Toshiba  Encoded stream reproducing apparatus 
US7164370B1 (en)  20051006  20070116  Analog Devices, Inc.  System and method for decoding data compressed in accordance with dictionarybased compression schemes 
US7164882B2 (en)  20021224  20070116  Poltorak Alexander I  Apparatus and method for facilitating a purchase using information provided on a media playing device 
US20070016594A1 (en)  20050715  20070118  Sony Corporation  Scalable video coding (SVC) file format 
JP2007013675A (en)  20050630  20070118  Sanyo Electric Co Ltd  Streaming distribution system and server 
US7168030B2 (en)  20031017  20070123  Telefonaktiebolaget Lm Ericsson (Publ)  Turbo code decoder with parity information update 
US20070022215A1 (en)  20050719  20070125  Singer David W  Method and apparatus for media data transmission 
US20070028099A1 (en)  20030911  20070201  Bamboo Mediacasting Ltd.  Secure multicast transmission 
EP1755248A1 (en)  20050819  20070221  BenQ Mobile GmbH & Co. OHG  Indication of lost segments across layer boundaries 
JP2007089137A (en)  20050919  20070405  Sharp Corp  Adaptive media playout by server media processing for performing robust streaming 
US20070078876A1 (en)  20050930  20070405  Yahoo! Inc.  Generating a stream of media data containing portions of media files using location tags 
US20070081562A1 (en)  20051011  20070412  Hui Ma  Method and device for stream synchronization of realtime multimedia transport over packet network 
US20070081586A1 (en)  20050927  20070412  Raveendran Vijayalakshmi R  Scalability techniques based on content information 
US7219289B2 (en)  20050315  20070515  Tandberg Data Corporation  Multiply redundant raid system and XORefficient method and apparatus for implementing the same 
US20070110074A1 (en)  20040604  20070517  Bob Bradley  System and Method for Synchronizing Media Presentation at Multiple Recipients 
US20070127576A1 (en)  20051207  20070607  Canon Kabushiki Kaisha  Method and device for decoding a scalable video stream 
WO2007042916B1 (en)  20051011  20070607  Nokia Corp  System and method for efficient scalable stream adaptation 
US7231404B2 (en)  20030131  20070612  Nokia Corporation  Datacast file transmission with metadata retention 
US20070134005A1 (en)  20051208  20070614  Electronics And Telecommunication Research Institute  Apparatus and method for generating returntozero signal 
JP2007158592A (en)  20051202  20070621  Nippon Telegr & Teleph Corp <Ntt>  Radio multicast transmission system, radio transmitter, and radio multicast transmission method 
US20070140369A1 (en)  20030707  20070621  Limberg Allen L  System of robust DTV signal transmissions that legacy DTV receivers will disregard 
US7240236B2 (en)  20040323  20070703  Archivas, Inc.  Fixed content distributed data storage using permutation ring encoding 
JP2007174170A (en)  20051221  20070705  Nippon Telegr & Teleph Corp <Ntt>  Apparatus, system, and program for transmitting and receiving packet 
US20070157267A1 (en)  20051230  20070705  Intel Corporation  Techniques to improve time seek operations 
US7243285B2 (en)  19980923  20070710  Digital Fountain, Inc.  Systems and methods for broadcasting information additive codes 
US20070162611A1 (en)  20060106  20070712  Google Inc.  Discontinuous Download of Media Files 
WO2007078253A2 (en)  20060105  20070712  Telefonaktiebolaget Lm Ericsson (Publ)  Media container file management 
US7249291B2 (en)  20020215  20070724  Digital Fountain, Inc.  System and method for reliably communicating the content of a live data stream 
US20070176800A1 (en)  20060130  20070802  International Business Machines Corporation  Fast data stream decoding using apriori information 
US20070177811A1 (en)  20060112  20070802  Lg Electronics Inc.  Processing multiview video 
US7254754B2 (en)  20030714  20070807  International Business Machines Corporation  Raid 3+3 
US20070185973A1 (en)  20060207  20070809  Dot Hill Systems, Corp.  Pull data replication model 
US7257764B2 (en)  20031103  20070814  Broadcom Corporation  FEC (Forward Error Correction) decoder with dynamic parameters 
WO2007090834A2 (en)  20060206  20070816  Telefonaktiebolaget Lm Ericsson (Publ)  Transporting packets 
US20070204196A1 (en)  20060213  20070830  Digital Fountain, Inc.  Streaming and buffering using variable fec overhead and protection periods 
US20070200949A1 (en)  20060221  20070830  Qualcomm Incorporated  Rapid tuning in multimedia applications 
US20070201549A1 (en)  20060111  20070830  Nokia Corporation  Backwardcompatible aggregation of pictures in scalable video coding 
JP2007228205A (en)  20060223  20070906  Funai Electric Co Ltd  Network server 
US20070230568A1 (en)  20060329  20071004  Alexandros Eleftheriadis  System And Method For Transcoding Between Scalable And NonScalable Video Codecs 
US20070233784A1 (en)  20010626  20071004  Microsoft Corporation  Wrapper Playlists on Streaming Media Services 
US20070255844A1 (en)  20060427  20071101  Microsoft Corporation  Guided random seek support for media streaming 
US7293222B2 (en)  20030129  20071106  Digital Fountain, Inc.  Systems and processes for fast encoding of hamming codes 
US7295573B2 (en)  20000819  20071113  Lg Electronics Inc.  Method for inserting length indicator in protocol data unit of radio link control 
US20070277209A1 (en)  20060524  20071129  Newport Media, Inc.  Robust transmission system and method for mobile television applications 
US7304990B2 (en)  20000203  20071204  Bandwiz Inc.  Method of encoding and transmitting data over a communication medium through division and segmentation 
US20070300127A1 (en)  20060510  20071227  Digital Fountain, Inc.  Code generator and decoder for communications systems operating using hybrid codes to allow for multiple efficient users of the communications systems 
US7318180B2 (en)  19980417  20080108  At&T Knowledge Ventures L.P.  Method and system for adaptive interleaving 
US20080010153A1 (en)  20060424  20080110  PughO'connor Archie  Computer network provided digital content under an advertising and revenue sharing basis, such as music provided via the internet with timeshifted advertisements presented by a client resident application 
US7320099B2 (en)  20040825  20080115  Fujitsu Limited  Method and apparatus for generating error correction data, and a computerreadable recording medium recording an error correction data generating program thereon 
JP2008011404A (en)  20060630  20080117  Toshiba Corp  Content processing apparatus and method 
WO2008011549A2 (en)  20060720  20080124  Sandisk Corporation  Content distribution system 
JP2008016907A (en)  20060703  20080124  Internatl Business Mach Corp <Ibm>  Encoding and decoding technique for packet recovery 
JP2008502212A (en)  20040601  20080124  クゥアルコム・インコーポレイテッドＱｕａｌｃｏｍｍ Ｉｎｃｏｒｐｏｒａｔｅｄ  How to improve the robustness of predictive video codec using a side channel based on the delivered source coding techniques, apparatus, and systems 
US20080052753A1 (en)  20060823  20080228  Mediatek Inc.  Systems and methods for managing television (tv) signals 
KR100809086B1 (en)  20030701  20080303  노키아 코포레이션  Progressive downloading of timed multimedia content 
US20080059532A1 (en)  20010118  20080306  Kazmi Syed N  Method and system for managing digital content, including streaming media 
US20080058958A1 (en)  20060609  20080306  Chia Pao Cheng  Knee joint with retention and cushion structures 
US20080066136A1 (en)  20060824  20080313  International Business Machines Corporation  System and method for detecting topic shift boundaries in multimedia streams using joint audio, visual and text cues 
JP2008508762A (en)  20040730  20080321  ノキア コーポレイション  Pointtopoint repair response mechanisms for pointtomultipoint transmission system 
US20080075172A1 (en)  20060925  20080327  Kabushiki Kaisha Toshiba  Motion picture encoding apparatus and method 
US7363048B2 (en)  20020415  20080422  Nokia Corporation  Apparatus, and associated method, for operating upon data at RLP logical layer of a communication station 
WO2008023328A3 (en)  20060824  20080424  Nokia Corp  System and method for indicating track relationships in media files 
US20080101478A1 (en)  20061031  20080501  Kabushiki Kaisha Toshiba  Decoding device and decoding method 
WO2008054100A1 (en)  20061101  20080508  Electronics And Telecommunications Research Institute  Method and apparatus for decoding metadata used for playing stereoscopic contents 
US7391717B2 (en)  20030630  20080624  Microsoft Corporation  Streaming of variable bit rate multimedia content 
US20080152241A1 (en)  20020710  20080626  Nec Corporation  Stereoscopic image encoding and decoding device multiplexing high resolution added images 
US7398454B2 (en)  20041221  20080708  Tyco Telecommunications (Us) Inc.  System and method for forward error correction decoding using soft information 
US20080168133A1 (en)  20070105  20080710  Roland Osborne  Video distribution system including progressive playback 
US20080168516A1 (en)  20070108  20080710  Christopher Lance Flick  Facilitating Random Access In Streaming Content 
US20080170564A1 (en)  20061114  20080717  Qualcomm Incorporated  Systems and methods for channel switching 
US20080170806A1 (en)  20070112  20080717  Samsung Electronics Co., Ltd.  3D image processing apparatus and method 
WO2008085013A1 (en)  20070112  20080717  UniversityIndustry Cooperation Group Of Kyung Hee University  Packet format of network abstraction layer unit, and algorithm and apparatus for video encoding and decoding using the format, qos control algorithm and apparatus for ipv6 label switching using the format 
US20080172430A1 (en)  20070111  20080717  Andrew Thomas Thorstensen  Fragmentation Compression Management 
US20080172712A1 (en)  20070111  20080717  Matsushita Electric Industrial Co., Ltd.  Multimedia data transmitting apparatus, multimedia data receiving apparatus, multimedia data transmitting method, and multimedia data receiving method 
US20080181296A1 (en)  20070116  20080731  Dihong Tian  Per multiblock partition breakpoint determining for hybrid variable length coding 
US7409626B1 (en)  20040728  20080805  Ikanos Communications Inc  Method and apparatus for determining codeword interleaver parameters 
US20080189419A1 (en)  20070202  20080807  David Andrew Girle  System and Method to Synchronize OSGi Bundle Inventories Between an OSGi Bundle Server and a Client 
US20080192818A1 (en)  20070209  20080814  Dipietro Donald Vincent  Systems and methods for securing media 
US20080215317A1 (en)  20040804  20080904  Dts, Inc.  Lossless multichannel audio codec using adaptive segmentation with random access point (RAP) and multiple prediction parameter set (MPPS) capability 
US20080232357A1 (en)  20070319  20080925  Legend Silicon Corp.  Ls digital fountain code 
US20080243918A1 (en)  20040330  20081002  Koninklijke Philips Electronic, N.V.  System and Method For Supporting Improved Trick Mode Performance For Disc Based Multimedia Content 
US20080256418A1 (en)  20060609  20081016  Digital Fountain, Inc  Dynamic stream interleaving and substream based delivery 
US20080281943A1 (en)  20011109  20081113  Jody Shapiro  System, method, and computer program product for remotely determining the configuration of a multimedia content user 
JP2008283571A (en)  20070511  20081120  Ntt Docomo Inc  Content distribution device, system and method 
JP2008283232A (en)  20070508  20081120  Sharp Corp  File reproduction device, file reproducing method, program executing file reproduction, and recording medium where the same program is recorded 
US20080285556A1 (en)  20070514  20081120  Samsung Electronics Co., Ltd.  Broadcasting service transmitting apparatus and method and broadcasting service receiving apparatus and method for effectively accessing broadcasting service 
JP2008543142A (en)  20050524  20081127  ノキア コーポレイション  Method and apparatus for hierarchical transmission and reception in the digital broadcast 
WO2008144004A1 (en)  20070516  20081127  Thomson Licensing  Apparatus and method for encoding and decoding signals 
US20080303893A1 (en)  20070611  20081211  Samsung Electronics Co., Ltd.  Method and apparatus for generating header information of stereoscopic image data 
WO2008148708A1 (en)  20070605  20081211  Thomson Licensing  Device and method for coding a video content in the form of a scalable stream 
US20080303896A1 (en)  20070607  20081211  Real D  Stereoplexing for film and video applications 
US20080313191A1 (en)  20070109  20081218  Nokia Corporation  Method for the support of file versioning in file repair 
WO2008156390A1 (en)  20070620  20081224  Telefonaktiebolaget Lm Ericsson (Publ)  Method and arrangement for improved media session management 
US20090003439A1 (en)  20070626  20090101  Nokia Corporation  System and method for indicating temporal layer switching points 
US20090019229A1 (en)  20070710  20090115  Qualcomm Incorporated  Data Prefetch Throttle 
US7483489B2 (en)  20020130  20090127  Nxp B.V.  Streaming multimedia data over a network having a variable bandwith 
JP2009027598A (en)  20070723  20090205  Hitachi Ltd  Video distribution server and video distribution method 
US20090043906A1 (en)  20070806  20090212  Hurst Mark B  Apparatus, system, and method for multibitrate content streaming 
US20090055705A1 (en)  20060208  20090226  Wen Gao  Decoding of Raptor Codes 
US20090067551A1 (en)  20070912  20090312  Digital Fountain, Inc.  Generating and communicating source identification information to enable reliable communications 
US20090083806A1 (en)  20031010  20090326  Microsoft Corporation  Media organization for distributed sending of media data 
US20090089445A1 (en)  20070928  20090402  Deshpande Sachin G  ClientControlled Adaptive Streaming 
EP2046044A1 (en)  20071001  20090408  Cabot Communications Ltd  A method and apparatus for streaming digital media content and a communication system 
US20090092138A1 (en)  20071009  20090409  Samsung Electronics Co. Ltd.  Apparatus and method for generating and parsing mac pdu in a mobile communication system 
US20090100496A1 (en)  20060424  20090416  Andreas Bechtolsheim  Media server system 
US20090103523A1 (en)  20071019  20090423  Rebelvox, Llc  Telecommunication and multimedia management method and apparatus 
US20090106356A1 (en)  20071019  20090423  Swarmcast, Inc.  Media playback point seeking using data range requests 
US7525994B2 (en)  20030130  20090428  Avaya Inc.  Packet data flow identification for multiplexing 
US7529806B1 (en)  19991104  20090505  Koninklijke Philips Electronics N.V.  Partitioning of MP3 content file for emulating streaming 
US20090125636A1 (en)  20071113  20090514  Qiong Li  Payload allocation methods for scalable multimedia servers 
RU2357279C2 (en)  20031215  20090527  Майкрософт Корпорейшн  System and control method and transmission of software updates 
WO2009065526A1 (en)  20071123  20090528  Media Patents S.L.  A process for the online distribution of audiovisual contents with advertisements, advertisement management system, digital rights management system and audiovisual content player provided with said systems 
US20090150557A1 (en)  20071205  20090611  Swarmcast, Inc.  Dynamic bit rate scaling 
US20090164653A1 (en)  20071224  20090625  Mandyam Giridhar D  Adaptive streaming for on demand wireless services 
US7555006B2 (en)  20030915  20090630  The Directv Group, Inc.  Method and system for adaptive transcoding and transrating in a video network 
US7559004B1 (en)  20031001  20090707  Sandisk Corporation  Dynamic redundant area configuration in a nonvolatile memory system 
JP2009171558A (en)  20071217  20090730  Canon Inc  Image processor, image managing server, and control method and program thereof 
JP2009527949A (en)  20060221  20090730  デジタル ファウンテン， インコーポレイテッド  Generation of manybody base code for a communication system device and the decoder 
US20090195640A1 (en)  20080131  20090806  Samsung Electronics Co., Ltd.  Method and apparatus for generating stereoscopic image data stream for temporally partial threedimensional (3d) data, and method and apparatus for displaying temporally partial 3d data of stereoscopic image 
US20090201990A1 (en)  20080204  20090813  AlcatelLucent  Method and device for reordering and multiplexing multimedia packets from multimedia streams pertaining to interrelated sessions 
US20090204877A1 (en)  20080213  20090813  Innovation Specialists, Llc  Block Modulus Coding (BMC) Systems and Methods for Block Coding with NonBinary Modulus 
EP2096870A2 (en)  20080228  20090902  Seiko Epson Corporation  Systems and methods for processing multiple projections of video data in a single video file 
US20090222873A1 (en)  20050307  20090903  Einarsson Torbjoern  Multimedia Channel Switching 
US7590118B2 (en)  20031223  20090915  Agere Systems Inc.  Frame aggregation format 
US20090248697A1 (en)  20080331  20091001  Richardson David R  Cache optimization 
US7597423B2 (en)  20021123  20091006  Silverbrook Research Pty Ltd  Printhead chip with high nozzle areal density 
US20090257508A1 (en)  20080410  20091015  Gaurav Aggarwal  Method and system for enabling video trick modes 
US7613183B1 (en)  20001031  20091103  Foundry Networks, Inc.  System and method for router data aggregation and delivery 
WO2009137705A2 (en)  20080507  20091112  Digital Fountain, Inc.  Fast channel zapping and high quality streaming protection over a broadcast channel 
US20090287841A1 (en)  20080512  20091119  Swarmcast, Inc.  Live media delivery over a packetbased computer network 
JP2009277182A (en)  20080519  20091126  Ntt Docomo Inc  Proxy server and communication relay program, and communication relaying method 
WO2009143741A1 (en)  20080529  20091203  腾讯科技（深圳）有限公司  Method, system and apparatus for playing media files on demand 
US20090300203A1 (en)  20080530  20091203  Microsoft Corporation  Stream selection for enhanced media streaming 
US7633970B2 (en)  20040507  20091215  Agere Systems Inc.  MAC header compression for use with frame aggregation 
US20090319563A1 (en)  20080621  20091224  Microsoft Corporation  File format for media distribution and presentation 
US20090328228A1 (en)  20080627  20091231  Microsoft Corporation  Segmented Media Content Rights Management 
US20100011117A1 (en)  20080709  20100114  Apple Inc.  Video streaming using multiple channels 
US20100011274A1 (en)  20080612  20100114  Qualcomm Incorporated  Hypothetical fec decoder and signalling for decoding control 
US20100011061A1 (en)  20020426  20100114  Hudson Michael D  Centralized selection of peers as media data sources in a dispersed peer network 
US7650036B2 (en)  20031016  20100119  Sharp Laboratories Of America, Inc.  System and method for threedimensional video coding 
US20100020871A1 (en)  20080421  20100128  Nokia Corporation  Method and Device for Video Coding and Decoding 
US20100049865A1 (en)  20080416  20100225  Nokia Corporation  Decoding Order Recovery in Session Multiplexing 
US20100046906A1 (en)  20050909  20100225  Panasonic Corporation  Image Processing Method, Image Recording Method, Image Processing Device and Image File Format 
US20100061444A1 (en)  20080911  20100311  On2 Technologies Inc.  System and method for video encoding using adaptive segmentation 
KR20100028156A (en)  20080904  20100312  에스케이 텔레콤주식회사  Media streaming system and method 
US20100067495A1 (en)  20061030  20100318  Young Dae Lee  Method of performing random access in a wireless communcation system 
EP1700410B1 (en)  20031207  20100428  Adaptive Spectrum and Signal Alignment, Inc.  Adaptive fec codeword management 
US7720096B2 (en)  20051013  20100518  Microsoft Corporation  RTP payload format for VC1 
US20100131671A1 (en)  20081124  20100527  Jaspal Kohli  Adaptive network content delivery system 
CN101729857A (en)  20091124  20100609  中兴通讯股份有限公司  Method for accessing video service and video playing system 
US20100153578A1 (en)  20080716  20100617  Nokia Corporation  Method and Apparatus for Peer to Peer Streaming 
US20100165077A1 (en)  20051019  20100701  Peng Yin  MultiView Video Coding Using Scalable Video Coding 
US20100174823A1 (en)  20060731  20100708  Juniper Networks, Inc.  Optimizing batch size for prefetching data over wide area networks 
US20100189131A1 (en)  20090123  20100729  Verivue, Inc.  Scalable seamless digital video stream splicing 
WO2010085361A2 (en)  20090126  20100729  Thomson Licensing  Frame packing for video coding 
WO2010088420A1 (en)  20090129  20100805  Dolby Laboratories Licensing Corporation  Methods and devices for subsampling and interleaving multiple images, eg stereoscopic 
US20100198982A1 (en)  20080318  20100805  Clarity Systems, S.L.  Methods for Transmitting Multimedia Files and Advertisements 
US20100211690A1 (en)  20090213  20100819  Digital Fountain, Inc.  Block partitioning for a data stream 
US20100223533A1 (en)  20090227  20100902  Qualcomm Incorporated  Mobile reception of digital video broadcastingterrestrial services 
US20100235528A1 (en)  20090316  20100916  Microsoft Corporation  Delivering cacheable streaming media presentations 
US20100235472A1 (en)  20090316  20100916  Microsoft Corporation  Smooth, stateless client media streaming 
WO2010120804A1 (en)  20090413  20101021  Reald Inc.  Encoding, decoding, and distributing enhanced resolution stereoscopic video 
US7831896B2 (en)  20030911  20101109  Runcom Technologies, Ltd.  Iterative forward error correction 
JP2010539832A (en)  20070921  20101216  フラウンホッファー−ゲゼルシャフト ツァ フェルダールング デァ アンゲヴァンテン フォアシュンク エー．ファオ  Information signal, apparatus and method for encoding information content, and an apparatus and method for error correction of the information signal 
US20100318632A1 (en)  20090616  20101216  Microsoft Corporation  Byte range caching 
WO2011038013A2 (en)  20090922  20110331  Qualcomm Incorporated  Enhanced blockrequest streaming system using signaling or block creation 
WO2011038034A1 (en)  20090922  20110331  Qualcomm Incorporated  Enhanced blockrequest streaming using cooperative parallel http and forward error correction 
US20110083144A1 (en)  20091006  20110407  Bocharov John A  Integrating continuous and sparse streaming data 
US7924913B2 (en)  20050915  20110412  Microsoft Corporation  Nonrealtime data transcoding of multimedia content 
JP2011087103A (en)  20091015  20110428  Sony Corp  Provision of content reproduction system, content reproduction device, program, content reproduction method, and content server 
US20110096828A1 (en)  20090922  20110428  Qualcomm Incorporated  Enhanced blockrequest streaming using scalable encoding 
US20110103519A1 (en)  20020611  20110505  Qualcomm Incorporated  Systems and processes for decoding chain reaction codes through inactivation 
WO2011059286A2 (en)  20091113  20110519  Samsung Electronics Co.,Ltd.  Method and apparatus for providing and receiving data 
US20110119396A1 (en)  20091113  20110519  Samsung Electronics Co., Ltd.  Method and apparatus for transmitting and receiving data 
US20110119394A1 (en)  20091104  20110519  Futurewei Technologies, Inc.  System and Method for Media Content Streaming 
WO2011070552A1 (en)  20091211  20110616  Nokia Corporation  Apparatus and methods for describing and timing representations in streaming media files 
US7979769B2 (en)  20080414  20110712  Lg Electronics Inc.  Method and apparatus for performing random access procedures 
WO2011102792A1 (en)  20100219  20110825  Telefonaktiebolaget L M Ericsson (Publ)  Method and arrangement for adaption in http streaming 
US20110216541A1 (en)  20100304  20110908  Ushio Denki Kabushiki Kaisha  Light source apparatus 
US20110231569A1 (en)  20090922  20110922  Qualcomm Incorporated  Enhanced blockrequest streaming using block partitioning or request controls for improved clientside handling 
US20110231519A1 (en)  20060609  20110922  Qualcomm Incorporated  Enhanced blockrequest streaming using url templates and construction rules 
US8028322B2 (en)  20050314  20110927  Time Warner Cable Inc.  Method and apparatus for network content download and recording 
US8027328B2 (en)  20061226  20110927  Alcatel Lucent  Header compression in a wireless communication network 
US20110268178A1 (en)  20090818  20111103  Anthony Neal Park  Encoding video streams for adaptive video streaming 
US20110280316A1 (en)  20100513  20111117  Qualcom Incorporated  Frame packing for asymmetric stereo video 
US20110299629A1 (en)  20090819  20111208  Qualcomm Incorporated  Methods and apparatus employing fec codes with permanent inactivation of symbols for encoding and decoding processes 
US20110307581A1 (en)  20100614  20111215  Research In Motion Limited  Media Presentation Description Delta File For HTTP Streaming 
US8081716B2 (en)  20060125  20111220  Lg Electronics Inc.  Digital broadcasting receiving system and method of processing data 
US20120016965A1 (en)  20100713  20120119  Qualcomm Incorporated  Video switching for streaming video data 
US20120013746A1 (en)  20100715  20120119  Qualcomm Incorporated  Signaling data for multiplexing video components 
US20120023254A1 (en)  20100720  20120126  UniversityIndustry Cooperation Group Of Kyung Hee University  Method and apparatus for providing multimedia streaming service 
US20120023249A1 (en)  20100720  20120126  Qualcomm Incorporated  Providing sequence data sets for streaming video data 
US20120020413A1 (en)  20100721  20120126  Qualcomm Incorporated  Providing frame packing type information for video coding 
US20120033730A1 (en)  20100809  20120209  Sony Computer Entertainment America, LLC.  Random access point (rap) formation using intra refreshing technique in video coding 
US20120042089A1 (en)  20100810  20120216  Qualcomm Incorporated  Trick modes for network streaming of coded multimedia data 
US20120047280A1 (en)  20100819  20120223  UniversityIndustry Cooperation Group Of Kyung Hee University  Method and apparatus for reducing deterioration of a quality of experience of a multimedia service in a multimedia system 
US8135073B2 (en)  20021219  20120313  Trident Microsystems (Far East) Ltd  Enhancing video images depending on prior image enhancements 
US20120099593A1 (en)  20090819  20120426  Qualcomm Incorporated  Universal file delivery methods for providing unequal error protection and bundled file delivery services 
US8185809B2 (en)  20010309  20120522  Digital Fountain, Inc.  Multioutput packet server with independent streams 
US20120151302A1 (en)  20101210  20120614  Qualcomm Incorporated  Broadcast multimedia storage and access using page maps when asymmetric memory is used 
US20120185530A1 (en)  20090722  20120719  Jigsee Inc.  Method of streaming media to heterogeneous client devices 
US20120202535A1 (en)  20030523  20120809  Navin Chaddha  Method And System For Communicating A Data File 
WO2012109614A1 (en)  20110211  20120816  Qualcomm Incorporated  Encoding and decoding using elastic codes with flexible source block mapping 
US20120208580A1 (en)  20110211  20120816  Qualcomm Incorporated  Forward error correction scheduling for an improved radio link protocol 
US20120207068A1 (en)  20110211  20120816  Qualcomm Incorporated  Framing for an improved radio link protocol including fec 
US8301725B2 (en)  20081231  20121030  Apple Inc.  Variant streams for realtime or near realtime streaming 
US8327403B1 (en)  20070907  20121204  United Video Properties, Inc.  Systems and methods for providing remote program ordering on a user device via a web server 
US20120317305A1 (en)  20100219  20121213  Telefonaktiebolaget Lm Ericsson (Publ)  Method and Arrangement for Representation Switching in HTTP Streaming 
US8340133B2 (en)  20051005  20121225  Lg Electronics Inc.  Method of processing traffic information and digital broadcast system 
US20130007223A1 (en)  20060609  20130103  Qualcomm Incorporated  Enhanced blockrequest streaming system for handling lowlatency streaming 
US20130002483A1 (en)  20050322  20130103  Qualcomm Incorporated  Methods and systems for deriving seed position of a subscriber station in support of unassisted gpstype position determination in a wireless communication system 
US20130091251A1 (en)  20111005  20130411  Qualcomm Incorporated  Network streaming of media data 
US8422474B2 (en)  20100311  20130416  Electronics & Telecommunications Research Institute  Method and apparatus for transceiving data in a MIMO system 
US8462643B2 (en)  20021025  20130611  Qualcomm Incorporated  MIMO WLAN system 
US20130246643A1 (en)  20110831  20130919  Qualcomm Incorporated  Switch signaling methods providing improved switching between representations for adaptive http streaming 
US20130254634A1 (en)  20120326  20130926  Qualcomm Incorporated  Universal object delivery and templatebased file delivery 
US8572646B2 (en)  20000407  20131029  Visible World Inc.  System and method for simultaneous broadcast for personalized messages 
US20130287023A1 (en)  20080702  20131031  Apple Inc.  Multimediaaware qualityofservice and error correction provisioning 
US8615023B2 (en)  20101027  20131224  Electronics And Telecommunications Research Institute  Apparatus and method for transmitting/receiving data in communication system 
US8638796B2 (en)  20080822  20140128  Cisco Technology, Inc.  Reordering segments of a large number of segmented service flows 
US8713624B1 (en)  19811103  20140429  Personalized Media Communications LLC  Signal processing apparatus and methods 
US8737421B2 (en)  20080904  20140527  Apple Inc.  MAC packet data unit construction for wireless systems 
Family Cites Families (2)
Publication number  Priority date  Publication date  Assignee  Title 

JP3167638B2 (en) *  19950804  20010521  三洋電機株式会社  Digital modulation method and the demodulation method and the digital modulation circuit and the demodulation circuit 
US8016422B2 (en) *  20081028  20110913  Eastman Kodak Company  Etendue maintaining polarization switching system and related methods 
Patent Citations (662)
Publication number  Priority date  Publication date  Assignee  Title 

US6185265B2 (en)  
US6373406B1 (en)  
US3909721A (en)  19720131  19750930  Signatron  Signal processing system 
US4365338A (en)  19800627  19821221  Harris Corporation  Technique for high rate digital transmission over a dynamic dispersive channel 
US8713624B1 (en)  19811103  20140429  Personalized Media Communications LLC  Signal processing apparatus and methods 
US4589112A (en)  19840126  19860513  International Business Machines Corporation  System for multiple error detection with single and double bit error correction 
US4901319A (en)  19880318  19900213  General Electric Company  Transmission system with adaptive interleaving 
US5153591A (en)  19880705  19921006  British Telecommunications Public Limited Company  Method and apparatus for encoding, decoding and transmitting data in compressed form 
US5136592A (en)  19890628  19920804  Digital Equipment Corporation  Error detection and correction system for long burst errors 
US20060244824A1 (en)  19890823  20061102  Debey Henry C  Method and system of program transmission optimization using a redundant transmission sequence 
US5701582A (en)  19890823  19971223  Delta Beta Pty. Ltd.  Method and apparatus for efficient transmissions of programs 
US5421031A (en)  19890823  19950530  Delta Beta Pty. Ltd.  Program transmission optimisation 
US5329369A (en)  19900601  19940712  Thomson Consumer Electronics, Inc.  Asymmetric picture compression 
US5455823A (en)  19901106  19951003  Radio Satellite Corporation  Integrated communications terminal 
US5524025A (en)  19901107  19960604  At&T Corp.  Coding for digital transmission 
US5465318A (en)  19910328  19951107  Kurzweil Applied Intelligence, Inc.  Method for generating a speech recognition model for a nonvocabulary utterance 
US5331320A (en)  19911121  19940719  International Business Machines Corporation  Coding method and apparatus using quaternary codes 
US5379297A (en)  19920409  19950103  Network Equipment Technologies, Inc.  Concurrent multichannel segmentation and reassembly processors for asynchronous transfer mode 
US5371532A (en)  19920515  19941206  Bell Communications Research, Inc.  Communications architecture and method for distributing information services 
US5425050A (en)  19921023  19950613  Massachusetts Institute Of Technology  Television transmission system using spread spectrum and orthogonal frequencydivision multiplex 
US5372532A (en)  19930126  19941213  Robertson, Jr.; George W.  Swivel head cap connector 
US5953537A (en)  19930212  19990914  Altera Corporation  Method and apparatus for reducing the number of programmable architecture elements required for implementing a lookup table in a programmable logic device 
US5583784A (en)  19930514  19961210  FraunhoferGesellschaft Zur Forderung Der Angewandten Forschung E.V.  Frequency analysis method 
US5642365A (en)  19930705  19970624  Mitsubishi Denki Kabushiki Kaisha  Transmitter for encoding error correction codes and a receiver for decoding error correction codes on a transmission frame 
JPH07183873A (en)  19931029  19950721  At & T Corp  Information transmitting method for communication system 
US5608738A (en)  19931110  19970304  Nec Corporation  Packet transmission method and apparatus 
US5517508A (en)  19940126  19960514  Sony Corporation  Method and apparatus for detection and error correction of packetized digital data 
EP0669587A2 (en)  19940224  19950830  AT&T Corp.  Networked system for display of multimedia presentations 
US5566208A (en)  19940317  19961015  Philips Electronics North America Corp.  Encoder buffer having an effective size which varies automatically with the channel bitrate 
US5432787A (en)  19940324  19950711  Loral Aerospace Corporation  Packet data transmission system with adaptive data recovery method 
US5757415A (en)  19940526  19980526  Sony Corporation  Ondemand data transmission by dividing input data into blocks and each block into subblocks such that the subblocks are rearranged for storage to data storage means 
US5802394A (en)  19940606  19980901  Starlight Networks, Inc.  Method for accessing one or more streams in a video storage system using multiple queues and maintaining continuity thereof 
US5568614A (en)  19940729  19961022  International Business Machines Corporation  Data streaming between peer subsystems of a computer system 
EP0853433A1 (en)  19940824  19980715  Macrovision Corporation  Method and apparatus for detecting a source identification signal in a video signal 
EP0701371A1 (en)  19940908  19960313  International Business Machines Corporation  Video optimised media streamer 
US5926205A (en)  19941019  19990720  Imedia Corporation  Method and apparatus for encoding and formatting data representing a video program to provide multiple overlapping presentations of the video program 
US5659614A (en)  19941128  19970819  Bailey, Iii; John E.  Method and system for creating and storing a backup copy of file data stored on a computer 
US5617541A (en)  19941221  19970401  International Computer Science Institute  System for packetizing data encoded corresponding to priority levels where reconstructed data corresponds to fractionalized priority level and received fractionalized packets 
JPH08186570A (en)  19941228  19960716  Toshiba Corp  Error control method in atm network 
US6061820A (en)  19941228  20000509  Kabushiki Kaisha Toshiba  Scheme for error control on ATM adaptation layer in ATM networks 
WO1996034463A1 (en)  19950427  19961031  Trustees Of The Stevens Institute Of Technology  High integrity transport for time critical multimedia networking applications 
US6079042A (en)  19950427  20000620  The Trustees Of The Stevens Institute Of Technology  High integrity transport for time critical multimedia networking applications 
US5993056A (en)  19950427  19991130  Stevens Institute Of Technology  High integrity transport for time critical multimedia networking applications 
US5835165A (en)  19950607  19981110  Lsi Logic Corporation  Reduction of false locking code words in concatenated decoders 
US5805825A (en)  19950726  19980908  Intel Corporation  Method for semireliable, unidirectional broadcast information services 
US6079041A (en)  19950804  20000620  Sanyo Electric Co., Ltd.  Digital modulation circuit and digital demodulation circuit 
US5754563A (en)  19950911  19980519  Ecc Technologies, Inc.  Byteparallel system for implementing reedsolomon errorcorrecting codes 
US5699473A (en)  19951010  19971216  Samsung Electronics Co., Ltd.  Method for recording and reproducing intercoded data using two levels of error correction 
US5751336A (en)  19951012  19980512  International Business Machines Corporation  Permutation based pyramid block transmission scheme for broadcasting in videoondemand storage systems 
EP0784401A2 (en)  19960112  19970716  Kabushiki Kaisha Toshiba  Digital broadcast receiving terminal apparatus 
US6012159A (en)  19960117  20000104  Kencast, Inc.  Method and system for errorfree data transfer 
US5852565A (en)  19960130  19981222  Demografx  Temporal and resolution layering in advanced television 
US5936659A (en)  19960131  19990810  Telcordia Technologies, Inc.  Method for video delivery using pyramid broadcasting 
US5903775A (en)  19960606  19990511  International Business Machines Corporation  Method for the sequential transmission of compressed video information at varying data rates 
WO1997050183A1 (en)  19960625  19971231  Telefonaktiebolaget Lm Ericsson (Publ)  Variable length coding with error protection 
JP2000513164A (en)  19960625  20001003  テレフオンアクチーボラゲツト エル エム エリクソン（パブル）  Error protection with variable length coding 
WO1998004973A1 (en)  19960726  19980205  Zenith Electronics Corporation  Data derotator and deinterleaver 
RU2189629C2 (en)  19960726  20020920  Зенит Электроникс Корпорейшн  Data endaround shift interleaving and re interleaving device 
US5936949A (en)  19960905  19990810  Netro Corporation  Wireless ATM metropolitan area network 
US20010033586A1 (en)  19961217  20011025  Satoru Takashimizu  Receiving apparatus for digital broadcasting signal and receving/recording/reproducing apparatus thereof 
US6141053A (en)  19970103  20001031  Saukkonen; Jukka I.  Method of optimizing bandwidth for transmitting compressed video data streams 
US6011590A (en)  19970103  20000104  Ncr Corporation  Method of transmitting compressed information to minimize buffer space 
US6044485A (en)  19970103  20000328  Ericsson Inc.  Transmitter method and transmission system using adaptive coding based on channel characteristics 
US5983383A (en)  19970117  19991109  Qualcom Incorporated  Method and apparatus for transmitting and receiving concatenated code data 
WO1998032256A1 (en)  19970117  19980723  Telefonaktiebolaget Lm Ericsson (Publ)  Apparatus, and associated method, for transmitting and receiving a multistage, encoded and interleaved digital communication signal 
WO1998032231A1 (en)  19970117  19980723  Qualcomm Incorporated  Method and apparatus for transmitting and receiving concatenated code data 
EP0854650A2 (en)  19970117  19980722  NOKIA TECHNOLOGY GmbH  Method for addressing a service in digital video broadcasting 
RU99117925A (en)  19970117  20010727  Телефонактиеболагет Лм Эрикссон (Пабл)  A method for transmitting and receiving a digital communications signal subjected to coding and multistage interleaving and an apparatus for its implementation 
US6014706A (en)  19970130  20000111  Microsoft Corporation  Methods and apparatus for implementing control functions in a streamed video display system 
EP1024672A1 (en)  19970307  20000802  Sanyo Electric Co., Ltd.  Digital broadcast receiver and display 
US7154951B2 (en)  19970314  20061226  Microsoft Corporation  Motion video signal encoder and encoding method 
US6005477A (en)  19970417  19991221  Abb Research Ltd.  Method and apparatus for information transmission via power supply lines 
US6226259B1 (en)  19970429  20010501  Canon Kabushiki Kaisha  Device and method for transmitting information device and method for processing information 
US5970098A (en)  19970502  19991019  Globespan Technologies, Inc.  Multilevel encoder 
US5844636A (en)  19970513  19981201  Hughes Electronics Corporation  Method and apparatus for receiving and recording digital packet data 
US20010015944A1 (en)  19970519  20010823  Sony Corporation  Recording method and apparatus for continuous playback of fragmented signals 
US6141787A (en)  19970519  20001031  Sanyo Electric Co., Ltd.  Digital modulation and demodulation 
US20050163468A1 (en)  19970519  20050728  Takao Takahashi  Signal recording method & apparatus, signal recording / reproducing method & apparatus and signal recording medium 
JPH1141211A (en)  19970519  19990212  Sanyo Electric Co Ltd  Digital modulatin circuit and its method, and digital demodulation circuit and its method 
EP0986908A1 (en)  19970602  20000322  Northern Telecom Limited  Dynamic selection of media streams for display 
US6081907A (en)  19970609  20000627  Microsoft Corporation  Data delivery system and method for delivering data and redundant information over a unidirectional network 
US5917852A (en)  19970611  19990629  L3 Communications Corporation  Data scrambling system and method and communications system incorporating same 
US6298462B1 (en)  19970625  20011002  Samsung Electronics Co., Ltd.  Data transmission method for dual diversity systems 
US6175944B1 (en)  19970715  20010116  Lucent Technologies Inc.  Methods and apparatus for packetizing data for transmission through an erasure broadcast channel 
US5933056A (en)  19970715  19990803  Exar Corporation  Single pole current mode commonmode feedback circuit 
JPH11112479A (en)  19970717  19990423  Hewlett Packard Co <Hp>  Device and method for ciphering 
US20030086515A1 (en)  19970731  20030508  Francois Trans  Channel adaptive equalization precoding system and method 
US6178536B1 (en)  19970814  20010123  International Business Machines Corporation  Coding scheme for file backup and systems based thereon 
US6393065B1 (en) *  19970829  20020521  Canon Kabushiki Kaisha  Coding and decoding methods and devices and equipment using them 
EP0903955A1 (en)  19970904  19990324  SGSTHOMSON MICROELECTRONICS S.r.l.  Modular architecture PET decoder for ATM networks 
US6088330A (en)  19970909  20000711  Bruck; Joshua  Reliable array of distributed computing nodes 
US6134596A (en)  19970918  20001017  Microsoft Corporation  Continuous media file server system and method for scheduling network resources to play multiple files having different data transmission rates 
US6272658B1 (en)  19971027  20010807  Kencast, Inc.  Method and system for reliable broadcasting of data files and streams 
US6195777B1 (en)  19971106  20010227  Compaq Computer Corporation  Loss resilient code with double heavy tailed series of redundant layers 
US6081909A (en)  19971106  20000627  Digital Equipment Corporation  Irregularly graphed encoding technique 
US6163870A (en)  19971106  20001219  Compaq Computer Corporation  Message encoding with irregular graphing 
US6081918A (en)  19971106  20000627  Spielman; Daniel A.  Loss resilient code with cascading series of redundant layers 
US6073250A (en)  19971106  20000606  Luby; Michael G.  Loss resilient decoding technique 
JPH11164270A (en)  19971125  19990618  Kdd  Method and device for transmitting video data using multi channel 
US6243846B1 (en)  19971212  20010605  3Com Corporation  Forward error correction system for packet based data and real time media, using crosswise parity calculation 
US5870412A (en)  19971212  19990209  3Com Corporation  Forward error correction system for packet based real time media 
US6849803B1 (en)  19980115  20050201  Arlington Industries, Inc.  Electrical connector 
US6097320A (en)  19980120  20000801  Silicon Systems, Inc.  Encoder/decoder system with suppressed error propagation 
US6226301B1 (en)  19980219  20010501  Nokia Mobile Phones Ltd  Method and apparatus for segmentation and assembly of data frames for retransmission in a telecommunications system 
US6141788A (en)  19980313  20001031  Lucent Technologies Inc.  Method and apparatus for forward error correction in packet networks 
US6278716B1 (en)  19980323  20010821  University Of Massachusetts  Multicast with proactive forward error correction 
US6459811B1 (en)  19980402  20021001  Sarnoff Corporation  Bursty data transmission of compressed video data 
US6185265B1 (en)  19980407  20010206  Worldspace Management Corp.  System for time division multiplexing broadcast channels with R1/2 or R3/4 convolutional coding for satellite transmission via onboard baseband processing payload or transparent payload 
US7318180B2 (en)  19980417  20080108  At&T Knowledge Ventures L.P.  Method and system for adaptive interleaving 
US6018359A (en)  19980424  20000125  Massachusetts Institute Of Technology  System and method for multicast videoondemand delivery system 
US6445717B1 (en)  19980501  20020903  Niwot Networks, Inc.  System for recovering lost information in a data stream 
US6421387B1 (en)  19980515  20020716  North Carolina State University  Methods and systems for forward error correction based loss recovery for interactive video transmission 
US6937618B1 (en)  19980520  20050830  Sony Corporation  Separating device and method and signal receiving device and method 
US6333926B1 (en)  19980811  20011225  Nortel Networks Limited  Multiple user CDMA basestation modem 
WO2000014921A1 (en)  19980904  20000316  At & T Corp.  Combined channel coding and spaceblock coding in a multiantenna arrangement 
US6415326B1 (en)  19980915  20020702  Microsoft Corporation  Timeline correlation between multiple timelinealtered media streams 
US7243285B2 (en)  19980923  20070710  Digital Fountain, Inc.  Systems and methods for broadcasting information additive codes 
US20080034273A1 (en)  19980923  20080207  Digital Fountain, Inc.  Information additive code generator and decoder for communication systems 
US7812743B2 (en)  19980923  20101012  Digital Fountain Inc.  Information additive code generator and decoder for communication systems 
EP1241795A2 (en)  19980923  20020918  Digital Fountain  Method and system for transmitting and receiving information using chain reaction codes 
US7057534B2 (en)  19980923  20060606  Digital Fountain, Inc.  Information additive code generator and decoder for communication systems 
US6614366B2 (en)  19980923  20030902  Digital Fountain, Inc.  Information additive code generator and decoder for communication systems 
JP3809957B2 (en)  19980923  20060816  デジタル ファウンテン， インコーポレイテッド  Packet transmission protocol recovery method lost packets 
US6307487B1 (en)  19980923  20011023  Digital Fountain, Inc.  Information additive code generator and decoder for communication systems 
US7233264B2 (en)  19980923  20070619  Digital Fountain, Inc.  Information additive code generator and decoder for communication systems 
JP3976163B2 (en)  19980923  20070912  デジタル ファウンテン， インコーポレイテッド  Packet transmission protocol recovery method lost packets 
US6320520B1 (en)  19980923  20011120  Digital Fountain  Information additive group code generator and decoder for communications systems 
US6373406B2 (en)  19980923  20020416  Digital Fountain, Inc.  Information additive code generator and decoder for communication systems 
WO2000018017A9 (en)  19980923  20011220  Digital Fountain  Lost packet recovery method for packet transmission protocols 
US6704370B1 (en)  19981009  20040309  Nortel Networks Limited  Interleaving methodology and apparatus for CDMA 
US6831172B1 (en)  19981111  20041214  FarmilaThea Farmaceutici S.P.A.  Crosslinked hyaluronic acids and medical uses thereof 
US20030194211A1 (en)  19981112  20031016  Max Abecassis  Intermittently playing a video 
US20050105371A1 (en)  19981116  20050519  Johnson Mark G.  Integrated circuit incorporating threedimensional memory array with dual opposing decoder arrangement 
JP2000151426A (en)  19981117  20000530  Toshiba Corp  Interleave and deinterleave circuit 
US6166544A (en)  19981125  20001226  General Electric Company  MR imaging system with interactive image contrast control 
US6876623B1 (en)  19981202  20050405  Agere Systems Inc.  Tuning scheme for code division multiplex broadcasting system 
US6314289B1 (en)  19981203  20011106  FraunhoferGesellschaft zur Förderung der angewandten Forschung e.V.  Apparatus and method for transmitting information and apparatus and method for receiving information 
US20040049793A1 (en)  19981204  20040311  Chou Philip A.  Multimedia presentation latency minimization 
US6496980B1 (en)  19981207  20021217  Intel Corporation  Method of providing replay on demand for streaming digital multimedia 
US6223324B1 (en)  19990105  20010424  Agere Systems Guardian Corp.  Multiple program unequal error protection for digital audio broadcasting and other applications 
JP2000216835A (en)  19990122  20000804  Hitachi Denshi Ltd  Receiver of soft decision decoding system of convolutional code 
US6618451B1 (en)  19990213  20030909  Altocom Inc  Efficient reduced state maximum likelihood sequence estimator 
US6041001A (en)  19990225  20000321  Lexar Media, Inc.  Method of increasing data reliability of a flash memory device without compromising compatibility 
WO2000052600A1 (en)  19990303  20000908  Sony Corporation  Transmitter, receiver, transmitter/receiver system, transmission method and reception method 
US6466698B1 (en)  19990325  20021015  The United States Of America As Represented By The Secretary Of The Navy  Efficient embedded image and video compression system using lifted wavelets 
US6535920B1 (en)  19990406  20030318  Microsoft Corporation  Analyzing, indexing and seeking of streaming information 
JP2000307435A (en)  19990406  20001102  Internatl Business Mach Corp <Ibm>  Coding circuit, circuit, parity generating method and storage medium 
US6609223B1 (en)  19990406  20030819  Kencast, Inc.  Method for packetlevel fec encoding, in which on a source packetbysource packet basis, the error correction contributions of a source packet to a plurality of wildcard packets are computed, and the source packet is transmitted thereafter 
US6804202B1 (en)  19990408  20041012  Lg Information And Communications, Ltd.  Radio protocol for mobile communication system and method 
US20050123058A1 (en)  19990427  20050609  Greenbaum Gary S.  System and method for generating multiple synchronized encoded representations of media data 
JP2002543705A (en)  19990429  20021217  ノキア コーポレイション  Data transmission 
EP1051027A1 (en)  19990506  20001108  Sony Corporation  Methods and apparatus for data processing, methods and apparatus for data reproducing and recording media 
US7068681B2 (en)  19990510  20060627  Samsung Electronics Co., Ltd.  Apparatus and method for exchanging variablelength data according to radio link protocol in mobile communication system 
US7483447B2 (en)  19990510  20090127  Samsung Electronics Co., Ltd  Apparatus and method for exchanging variablelength data according to radio link protocol in mobile communication system 
US7100188B2 (en)  19990526  20060829  Enounce, Inc.  Method and apparatus for controlling timescale modification during multimedia broadcasts 
US6154452A (en)  19990526  20001128  Xm Satellite Radio Inc.  Method and apparatus for continuous crosschannel interleaving 
US6229824B1 (en)  19990526  20010508  Xm Satellite Radio Inc.  Method and apparatus for concatenated convolutional endcoding and interleaving 
JP2000353969A (en)  19990611  20001219  Sony Corp  Receiver for digital voice broadcasting 
US6577599B1 (en)  19990630  20030610  Sun Microsystems, Inc.  Smallscale reliable multicasting 
US6751772B1 (en)  19990706  20040615  Samsung Electronics Co., Ltd.  Rate matching device and method for a data communication system 
US6643332B1 (en)  19990709  20031104  Lsi Logic Corporation  Method and apparatus for multilevel coding of digital signals 
JP2001036417A (en)  19990722  20010209  Japan Radio Co Ltd  Device, method and medium for correcting and encoding error, and device, method and medium for decoding error correction code 
US6584543B2 (en)  19990722  20030624  Micron Technology, Inc.  Reconfigurable memory with selectable error correction storage 
JP2003507985A (en)  19990804  20030225  サン・マイクロシステムズ・インコーポレイテッド  System and method for detecting a 2bit error, to correct the errors due to failures of the components 
EP1124344A1 (en)  19990820  20010816  Matsushita Electric Industrial Co., Ltd.  Ofdm communication device 
US6430233B1 (en)  19990830  20020806  Hughes Electronics Corporation  SingleLNB satellite data receiver 
US6332163B1 (en)  19990901  20011218  Accenture, Llp  Method for providing communication services over a computer network system 
US6882618B1 (en)  19990907  20050419  Sony Corporation  Transmitting apparatus, receiving apparatus, communication system, transmission method, reception method, and communication method 
WO2001020786A1 (en)  19990917  20010322  Digital Fountain  Group chain reaction encoder with variable number of associated input data for each output group code 
JP2001189665A (en)  19990917  20010710  Digital Fountain  Information additive group code generator and decoder for communication system 
JP2003510734A (en)  19990927  20030318  コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ  Files divided for streaming emulate 
JP2001094625A (en)  19990927  20010406  Canon Inc  Data communication unit, data communication method and storage medium 
US20050160272A1 (en)  19991028  20050721  Timecertain, Llc  System and method for providing trusted time in content of digital data files 
US7529806B1 (en)  19991104  20090505  Koninklijke Philips Electronics N.V.  Partitioning of MP3 content file for emulating streaming 
US6523147B1 (en)  19991111  20030218  Ibiquity Digital Corporation  Method and apparatus for forward error correction coding for an AM inband onchannel digital audio broadcasting system 
US20050018635A1 (en)  19991122  20050127  Ipr Licensing, Inc.  Variable rate coding for forward link 
CN1425228A (en)  19991122  20030618  讯捷通讯公司  Variable rate coding for forward link 
US6748441B1 (en)  19991202  20040608  Microsoft Corporation  Data carousel receiving and caching 
US6678855B1 (en)  19991202  20040113  Microsoft Corporation  Selecting K in a data transmission carousel using (N,K) forward error correction 
JP2001223655A (en)  19991216  20010817  Lucent Technol Inc  Cluster frame synchronization scheme for satellite digital audio radio system 
US6487692B1 (en)  19991221  20021126  Lsi Logic Corporation  ReedSolomon decoder 
US20020009137A1 (en)  20000201  20020124  Nelson John E.  Threedimensional video broadcasting system 
US6965636B1 (en)  20000201  20051115  2Wire, Inc.  System and method for block error correction in packetbased digital communications 
WO2001057667A1 (en)  20000203  20010809  Bandwiz, Inc.  Data streaming 
WO2001058130A2 (en)  20000203  20010809  Bandwiz, Inc.  Coding method 
US7304990B2 (en)  20000203  20071204  Bandwiz Inc.  Method of encoding and transmitting data over a communication medium through division and segmentation 
WO2001058131A2 (en)  20000203  20010809  Bandwiz, Inc.  Broadcast system 
JP2001251287A (en)  20000224  20010914  Geneticware Corp Ltd  Confidential transmitting method using hardware protection inside secret key and variable pass code 
JP2001274855A (en)  20000229  20011005  Koninkl Philips Electronics Nv  Receiver and method for detecting and demodulating received signal subjected to dqpsk modulation and channel encoding 
US6765866B1 (en)  20000229  20040720  Mosaid Technologies, Inc.  Link aggregation 
US6420982B1 (en)  20000323  20020716  Mosaid Technologies, Inc.  Multistage lookup for translating between signals of different bit lengths 
JP2001274776A (en)  20000324  20011005  Toshiba Corp  Information data transmission system and its transmitter and receiver 
US6510177B1 (en)  20000324  20030121  Microsoft Corporation  System and method for layered video coding enhancement 
US20020053062A1 (en)  20000331  20020502  Ted Szymanski  Transmitter, receiver, and coding scheme to increase data rate and decrease bit error rate of an optical data link 
US6473010B1 (en)  20000404  20021029  Marvell International, Ltd.  Method and apparatus for determining error correction code failure rate for iterative decoding algorithms 
US8572646B2 (en)  20000407  20131029  Visible World Inc.  System and method for simultaneous broadcast for personalized messages 
US7073191B2 (en)  20000408  20060704  Sun Microsystems, Inc  Streaming a single media track to multiple clients 
US6631172B1 (en) *  20000501  20031007  Lucent Technologies Inc.  Efficient list decoding of ReedSolomon codes for message recovery in the presence of high noise levels 
US6742154B1 (en)  20000525  20040525  Ciena Corporation  Forward error correction codes for digital optical network optimization 
US6694476B1 (en)  20000602  20040217  Vitesse Semiconductor Corporation  Reedsolomon encoder and decoder 
US6810499B2 (en)  20000602  20041026  Vitesse Semiconductor Corporation  Product code based forward error correction system 
CN1338839A (en)  20000810  20020306  扎尔林克半导体股份有限公司  Codes for combining ReedSolomen and Teb Technologies 
US20020083345A1 (en)  20000816  20020627  Halliday David C.  Method and system for secure communication over unstable public connections 
US7668198B2 (en)  20000819  20100223  Lg Electronics Inc.  Method for inserting length indicator in protocol data unit of radio link control 
US7295573B2 (en)  20000819  20071113  Lg Electronics Inc.  Method for inserting length indicator in protocol data unit of radio link control 
JP2002073625A (en)  20000824  20020312  Nippon Hoso Kyokai <Nhk>  Method server and medium for providing information synchronously with broadcast program 
US20040117716A1 (en)  20000920  20040617  Qiang Shen  Single engine turbo decoder with single frame size buffer for interleaving/deinterleaving 
US6486803B1 (en)  20000922  20021126  Digital Fountain, Inc.  On demand encoding with a window 
US7031257B1 (en)  20000922  20060418  Lucent Technologies Inc.  Radio link protocol (RLP)/pointtopoint protocol (PPP) design that passes corrupted data and error location information among layers in a wireless data transmission protocol 
US7151754B1 (en)  20000922  20061219  Lucent Technologies Inc.  Complete user datagram protocol (CUDP) for wireless multimedia packet networks using improved packet level forward error correction (FEC) coding 
WO2002027988A2 (en)  20000929  20020404  Visible World, Inc.  System and method for seamless switching 
US6411223B1 (en)  20001018  20020625  Digital Fountain, Inc.  Generating high weight encoding symbols using a basis 
US7613183B1 (en)  20001031  20091103  Foundry Networks, Inc.  System and method for router data aggregation and delivery 
JP2002204219A (en)  20001107  20020719  Agere Systems Guardian Corp  Smalldelay communication path code for correcting burst of loss packet 
US6732325B1 (en)  20001108  20040504  Digeo, Inc.  Errorcorrection with limited working storage 
US20020133247A1 (en)  20001111  20020919  Smith Robert D.  System and method for seamlessly switching between media streams 
US7512697B2 (en)  20001113  20090331  Digital Fountain, Inc.  Scheduling of multiple files for serving on a server 
US20090210547A1 (en)  20001113  20090820  Digital Fountain, Inc.  Scheduling of multiple files for serving on a server 
US7072971B2 (en)  20001113  20060704  Digital Foundation, Inc.  Scheduling of multiple files for serving on a server 
US7240358B2 (en)  20001208  20070703  Digital Fountain, Inc.  Methods and apparatus for scheduling, serving, receiving mediaon demand for clients, servers arranged according to constraints on resources 
WO2002047391A1 (en)  20001208  20020613  Digital Fountain, Inc.  Methods and apparatus for scheduling, serving, receiving mediaondemand for clients, servers arranged according to constraints on resources 
US20080086751A1 (en)  20001208  20080410  Digital Fountain, Inc.  Methods and apparatus for scheduling, serving, receiving mediaondemand for clients, servers arranged according to constraints on resources 
JP2004516717A (en)  20001215  20040603  ブリティッシュ・テレコミュニケーションズ・パブリック・リミテッド・カンパニーＢｒｉｔｉｓｈ Ｔｅｌｅｃｏｍｍｕｎｉｃａｔｉｏｎｓ Ｐｕｂｌｉｃ Ｌｉｍｉｔｅｄ Ｃｏｍｐａｎｙ  Audio and, or transmission and reception of video material 
EP2071827A2 (en)  20001215  20090617  British Telecommunications Public Limited Company  Transmission and reception of audio and/or video material 
CN1481643A (en)  20001215  20040310  英国电讯有限公司  Transmission and reception of audio and/or video material 
US6850736B2 (en)  20001221  20050201  Tropian, Inc.  Method and apparatus for reception quality indication in wireless communication 
US7143433B1 (en)  20001227  20061128  Infovalve Computing Inc.  Video distribution system using dynamic segmenting of video data files 
US20020085013A1 (en)  20001229  20020704  Lippincott Louis A.  Scan synchronized dual frame buffer graphics subsystem 
US20040031054A1 (en)  20010104  20040212  Harald Dankworth  Methods in transmission and searching of video information 
US20080059532A1 (en)  20010118  20080306  Kazmi Syed N  Method and system for managing digital content, including streaming media 
US6641366B2 (en)  20010126  20031104  Thorsten Nordhoff  Wind power generating system with an obstruction lighting or night marking device 
KR20030071815A (en)  20010208  20030906  노키아 코포레이션  Method and system for buffering streamed data 
WO2002063461A1 (en)  20010208  20020815  Nokia Corporation  Method and system for buffering streamed data 
US6868083B2 (en)  20010216  20050315  HewlettPackard Development Company, L.P.  Method and system for packet communication employing path diversity 
JP2004529533A (en)  20010216  20040924  ヒューレット・パッカード・カンパニーＨｅｗｌｅｔｔ−Ｐａｃｋａｒｄ Ｃｏｍｐａｎｙ  Method and system for packet communications utilizing the route diversity 
US8185809B2 (en)  20010309  20120522  Digital Fountain, Inc.  Multioutput packet server with independent streams 
US20020141433A1 (en)  20010330  20021003  Samsung Electronics Co., Ltd.  Apparatus and method for efficiently distributing packet data channel in a mobile communication system for high rate packet transmission 
US20020143953A1 (en)  20010403  20021003  International Business Machines Corporation  Automatic affinity within networks performing workload balancing 
US20050138286A1 (en)  20010411  20050623  Franklin Chris R.  Inplace data transformation for faulttolerant disk storage systems 
US6820221B2 (en)  20010413  20041116  HewlettPackard Development Company, L.P.  System and method for detecting process and network failures in a distributed system 
US7010052B2 (en)  20010416  20060307  The Ohio University  Apparatus and method of CTCM encoding and decoding for a digital communication system 
US20040096110A1 (en)  20010420  20040520  Front Porch Digital Inc.  Methods and apparatus for archiving, indexing and accessing audio and video data 
US20020191116A1 (en)  20010424  20021219  Damien Kessler  System and data format for providing seamless stream switching in a digital video recorder 
US6497479B1 (en)  20010427  20021224  HewlettPackard Company  Higher organic inks with good reliability and drytime 
US20060212444A1 (en)  20010516  20060921  Pandora Media, Inc.  Methods and systems for utilizing contextual feedback to generate and modify playlists 
US6633856B2 (en)  20010615  20031014  Flarion Technologies, Inc.  Methods and apparatus for decoding LDPC codes 
US20070233784A1 (en)  20010626  20071004  Microsoft Corporation  Wrapper Playlists on Streaming Media Services 
JP2003092564A (en)  20010628  20030328  Microsoft Corp  Negotiated/dynamic error correction for streamed media 
US20030005386A1 (en)  20010628  20030102  Sanjay Bhatt  Negotiated/dynamic error correction for streamed media 
JP2003018568A (en)  20010629  20030117  Matsushita Electric Ind Co Ltd  Reproducing system, server apparatus and reproducer 
US6895547B2 (en)  20010711  20050517  International Business Machines Corporation  Method and apparatus for low density parity check encoding of data 
US6928603B1 (en)  20010719  20050809  Adaptix, Inc.  System and method for interference mitigation using adaptive forward error correction in a wireless RF data transmission system 
US20030037299A1 (en)  20010816  20030220  Smith Kenneth Kay  Dynamic variablelength error correction code 
US7110412B2 (en)  20010918  20060919  Sbc Technology Resources, Inc.  Method and system to transport highquality video signals 
EP1298931A2 (en)  20010920  20030402  Oplayo Oy  Adaptive media stream 
US20030106014A1 (en)  20011012  20030605  Ralf Dohmen  High speed syndromebased FEC encoder and decoder and system using same 
US20080281943A1 (en)  20011109  20081113  Jody Shapiro  System, method, and computer program product for remotely determining the configuration of a multimedia content user 
RU2297663C2 (en)  20011129  20070420  Нокиа Корпорейшн  System and method for identification and accessing network services 
WO2003046742A1 (en)  20011129  20030605  Nokia Corporation  System and method for identifying and accessing network services 
US20030101408A1 (en)  20011129  20030529  Emin Martinian  Apparatus and method for adaptive, multimode decoding 
JP2003174489A (en)  20011205  20030620  Ntt Docomo Inc  Streaming distribution device and streaming distribution method 
US7068729B2 (en)  20011221  20060627  Digital Fountain, Inc.  Multistage code generator and decoder for communication systems 
EP1468497A1 (en)  20011221  20041020  Digital Fountain, Inc.  Multi; stage code generator and decoder for communication systems 
US7720174B2 (en)  20011221  20100518  Digital Fountain, Inc.  Multistage code generator and decoder for communication systems 
US20110019769A1 (en)  20011221  20110127  Qualcomm Incorporated  Multi stage code generator and decoder for communication systems 
US20080309525A1 (en)  20011221  20081218  Digital Fountain, Inc.  Multistage code generator and decoder for communication systems 
WO2003056703A1 (en)  20011221  20030710  Digital Fountain, Inc.  Multistage code generator and decoder for communication systems 
CN1819661A (en)  20020123  20060816  诺基亚有限公司  Grouping of image frames in video coding 
US20060120464A1 (en)  20020123  20060608  Nokia Corporation  Grouping of image frames in video coding 
US20030138043A1 (en)  20020123  20030724  Miska Hannuksela  Grouping of image frames in video coding 
US7483489B2 (en)  20020130  20090127  Nxp B.V.  Streaming multimedia data over a network having a variable bandwith 
US7249291B2 (en)  20020215  20070724  Digital Fountain, Inc.  System and method for reliably communicating the content of a live data stream 
JP2003256321A (en)  20020228  20030912  Nec Corp  Proxy server and proxy control program 
JP2003333577A (en)  20020306  20031121  Hewlett Packard Co <Hp>  Medium streaming distribution system 
US20050180415A1 (en)  20020306  20050818  Gene Cheung  Medium streaming distribution system 
KR20030074386A (en)  20020315  20030919  톰슨 라이센싱 소시에떼 아노님  Device and method for inserting error correcting codes and for reconstructing data streams, and corresponding products 
US20040015768A1 (en)  20020315  20040122  Philippe Bordes  Device and method for inserting error correcting codes and for reconstructing data streams, and corresponding products 
US7363048B2 (en)  20020415  20080422  Nokia Corporation  Apparatus, and associated method, for operating upon data at RLP logical layer of a communication station 
US6677864B2 (en)  20020418  20040113  Telefonaktiebolaget L.M. Ericsson  Method for multicast over wireless networks 
JP2003319012A (en)  20020419  20031107  Matsushita Electric Ind Co Ltd  Data receiver and data distribution system 
JP2003318975A (en)  20020419  20031107  Matsushita Electric Ind Co Ltd  Data receiving apparatus and data distribution system 
US20040240382A1 (en)  20020419  20041202  Daiji Ido  Data reception apparatus and data distribution system 
EP1501318A1 (en)  20020425  20050126  Sharp Corporation  Image encodder, image decoder, record medium, and image recorder 
US20100011061A1 (en)  20020426  20100114  Hudson Michael D  Centralized selection of peers as media data sources in a dispersed peer network 
US20030207696A1 (en)  20020506  20031106  Serge Willenegger  Multimedia broadcast and multicast service (MBMS) in a wireless communications system 
US20030224773A1 (en)  20020531  20031204  Douglas Deeds  Fragmented delivery of multimedia 
WO2003105484A1 (en)  20020611  20031218  Telefonaktiebolaget L M Ericsson (Publ)  Generation of mixed media streams 
US20100103001A1 (en)  20020611  20100429  Qualcomm Incorporated  Methods and apparatus employing fec codes with permanent inactivation of symbols for encoding and decoding processes 
WO2003105350A1 (en)  20020611  20031218  Digital Fountain, Inc.  Decoding of chain reaction codes through inactivation of recovered symbols 
US7956772B2 (en) *  20020611  20110607  Qualcomm Incorporated  Methods and apparatus employing FEC codes with permanent inactivation of symbols for encoding and decoding processes 
US7570665B2 (en)  20020611  20090804  Telefonaktiebolaget L M Ericsson (Publ)  Generation of mixed media streams 
US6856263B2 (en)  20020611  20050215  Digital Fountain, Inc.  Systems and processes for decoding chain reaction codes through inactivation 
US7030785B2 (en)  20020611  20060418  Digital Fountain, Inc.  Systems and processes for decoding a chain reaction code through inactivation 
US7633413B2 (en)  20020611  20091215  Qualcomm Incorporated  Systems and processes for decoding a chain reaction code through inactivation 
US7265688B2 (en)  20020611  20070904  Digital Fountain, Inc.  Systems and processes for decoding a chain reaction code through inactivation 
US20110103519A1 (en)  20020611  20110505  Qualcomm Incorporated  Systems and processes for decoding chain reaction codes through inactivation 
US6956875B2 (en)  20020619  20051018  Atlinks Usa, Inc.  Technique for communicating variable bit rate data over a constant bit rate link 
US20080152241A1 (en)  20020710  20080626  Nec Corporation  Stereoscopic image encoding and decoding device multiplexing high resolution added images 
JP2004048704A (en)  20020712  20040212  Sumitomo Electric Ind Ltd  Method and device for generating transmission data 
US20040066854A1 (en)  20020716  20040408  Hannuksela Miska M.  Method for random access and gradual picture refresh in video coding 
WO2004008735A2 (en)  20020716  20040122  Nokia Corporation  A method for random access and gradual picture refresh in video coding 
WO2004019521A1 (en)  20020731  20040304  Sharp Kabushiki Kaisha  Data communication device, its intermittent communication method, program describing its method, and recording medium on which program is recorded 
JP2004070712A (en)  20020807  20040304  Nippon Telegr & Teleph Corp <Ntt>  Data delivery method, data delivery system, split delivery data receiving method, split delivery data receiving device and split delivery data receiving program 
WO2004015948A1 (en)  20020813  20040219  Nokia Corporation  Symbol interleaving 
US6985459B2 (en)  20020821  20060110  Qualcomm Incorporated  Early transmission and playout of packets in wireless communication systems 
WO2004030273A1 (en)  20020927  20040408  Fujitsu Limited  Data delivery method, system, transfer method, and program 
EP1406452A2 (en)  20021003  20040407  NTT DoCoMo, Inc.  Video signal encoding and decoding method 
US7394407B2 (en)  20021005  20080701  Digital Fountain, Inc.  Systematic encoding and decoding of chain reaction codes 
WO2004034589A2 (en)  20021005  20040422  Digital Fountain, Inc.  Systematic encoding and decoding of chain reaction codes 
US7532132B2 (en)  20021005  20090512  Digital Fountain, Inc.  Systematic encoding and decoding of chain reaction codes 
US20090189792A1 (en)  20021005  20090730  Shokrollahi M Amin  Systematic encoding and decoding of chain reaction codes 
USRE43741E1 (en)  20021005  20121016  Qualcomm Incorporated  Systematic encoding and decoding of chain reaction codes 
US6909383B2 (en)  20021005  20050621  Digital Fountain, Inc.  Systematic encoding and decoding of chain reaction codes 
JP2004135013A (en)  20021010  20040430  Matsushita Electric Ind Co Ltd  Device and method for transmission 
JP2006503463A (en)  20021014  20060126  ノキア コーポレイション  Streaming media 
WO2004036824A1 (en)  20021014  20040429  Nokia Corporation  Streaming media 
US20040081106A1 (en)  20021025  20040429  Stefan Bruhn  Delay trading between communication links 
US8462643B2 (en)  20021025  20130611  Qualcomm Incorporated  MIMO WLAN system 
CN1708934A (en)  20021030  20051214  皇家飞利浦电子股份有限公司  Adaptative forward error control scheme 
WO2004040831A1 (en)  20021030  20040513  Koninklijke Philips Electronics N.V.  Adaptative forward error control scheme 
US20060031738A1 (en)  20021030  20060209  Koninklijke Philips Electronics, N.V.  Adaptative forward error control scheme 
JP2006505177A (en)  20021030  20060209  コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィＫｏｎｉｎｋｌｉｊｋｅ Ｐｈｉｌｉｐｓ Ｅｌｅｃｔｒｏｎｉｃｓ Ｎ．Ｖ．  Adaptive forward error control scheme 
JP2004165922A (en)  20021112  20040610  Sony Corp  Apparatus, method, and program for information processing 
JP2006506926A (en)  20021118  20060223  ブリティッシュ・テレコミュニケーションズ・パブリック・リミテッド・カンパニーＢｒｉｔｉｓｈ Ｔｅｌｅｃｏｍｍｕｎｉｃａｔｉｏｎｓ Ｐｕｂｌｉｃ Ｌｉｍｉｔｅｄ Ｃｏｍｐａｎｙ  A method of transmitting video 
WO2004047455A1 (en)  20021118  20040603  British Telecommunications Public Limited Company  Transmission of video 
CN1714577A (en)  20021118  20051228  英国电讯有限公司  Transmission of video 
WO2004047019A2 (en)  20021121  20040603  Electronics And Telecommunications Research Institute  Encoder using low density parity check codes and encoding method thereof 
US7597423B2 (en)  20021123  20091006  Silverbrook Research Pty Ltd  Printhead chip with high nozzle areal density 
JP2004192140A (en)  20021209  20040708  Sony Corp  Data communication system, data transmitting device, data receiving device and method, and computer program 
JP2004193992A (en)  20021211  20040708  Sony Corp  Information processing system, information processor, information processing method, recording medium and program 
US8135073B2 (en)  20021219  20120313  Trident Microsystems (Far East) Ltd  Enhancing video images depending on prior image enhancements 
US7164882B2 (en)  20021224  20070116  Poltorak Alexander I  Apparatus and method for facilitating a purchase using information provided on a media playing device 
US7293222B2 (en)  20030129  20071106  Digital Fountain, Inc.  Systems and processes for fast encoding of hamming codes 
US7525994B2 (en)  20030130  20090428  Avaya Inc.  Packet data flow identification for multiplexing 
US20040151109A1 (en)  20030130  20040805  Anuj Batra  Timefrequency interleaved orthogonal frequency division multiplexing ultra wide band physical layer 
US7231404B2 (en)  20030131  20070612  Nokia Corporation  Datacast file transmission with metadata retention 
US20040162071A1 (en)  20030218  20040819  Francesco Grilli  Method and apparatus to track count of broadcast content recipients in a wireless telephone network 
EP1455504A2 (en)  20030307  20040908  Samsung Electronics Co., Ltd.  Apparatus and method for processing audio signal and computer readable recording medium storing computer program for the method 
JP2004289621A (en)  20030324  20041014  Fujitsu Ltd  Data transmission server 
US20060020796A1 (en)  20030327  20060126  Microsoft Corporation  Human input security codes 
WO2004088988A1 (en)  20030331  20041014  Sharp Kabushiki Kaisha  Video encoder and method of encoding video 
JP2006519517A (en)  20030331  20060824  シャープ株式会社  Method of encoding a video encoder and video 
US20040207548A1 (en)  20030421  20041021  Daniel Kilbank  System and method for using a microletbased modem 
JP2004343701A (en)  20030421  20041202  Matsushita Electric Ind Co Ltd  Data receiving reproduction apparatus, data receiving reproduction method, and data receiving reproduction processing program 
US20050041736A1 (en)  20030507  20050224  Bernie ButlerSmith  Stereoscopic television signal processing method, transmission system and viewer enhancements 
US20040231004A1 (en)  20030513  20041118  Lg Electronics Inc.  HTTP based video streaming apparatus and method in mobile communication system 
CN1792056A (en)  20030516  20060621  高通股份有限公司  Reliable reception of broadcast/multicast content 
JP2004348824A (en)  20030521  20041209  Toshiba Corp  Ecc encoding method and ecc encoding device 
US20120202535A1 (en)  20030523  20120809  Navin Chaddha  Method And System For Communicating A Data File 
JP2004362099A (en)  20030603  20041224  Sony Corp  Server device, information processor, information processing method, and computer program 
RU2312390C2 (en)  20030607  20071210  Самсунг Электроникс Ко., Лтд.  Device and method for organization and interpretation of multimedia data on recordable information carrier 
WO2004109538A1 (en)  20030607  20041216  Samsung Electronics Co. Ltd.  Apparatus and method for organization and interpretation of multimedia data on a recording medium 